Stria Terminalis Nucleus Research Articles

Regulation of Feeding Behavior by Optogenetic Activation of Inputs to Lateral Hypothalamus

The bed nucleus stria terminalis (BNST) and parabrachial nucleus (PBN) are two brain regions in correspondence with the lateral hypothalamic area (LHA) that are responsible for regulating feeding behavior in mice. It is acknowledged that increasing the activity of GABAergic BNST inputs (which release the inhibitory neurotransmitter GABA) to the LHA inhibits LHA glutamate neurons and increases feeding, whereas increasing activity of glutamatergic PBN inputs (which release the excitatory neurotransmitter glutamate) to the LHA excites local glutamate neurons and decreases feeding. Obesity is a prevalent problem in our society, and therefore it is important to understand the reasons behind excessive food intake habits of humans. To address this issue, we tested for effects of activating the BNST-LHA and PBN-LHA pathways in relation to the satiety state of the mice. We stimulated the BNST and PBN inputs to LHA in fasted and fed mice. We tested the effects of Satiety State (fed vs. fasted) and stimulation Frequency (5-40 Hz) on sucrose seeking behavior of two Groups of mice (ChR2 vs YFP controls). The BNST-LHA pathway tended to show a general increase in feeding behaviors, while the PBN-LHA pathway did not show a significant effect of activation. From these results, further studies can be conducted to explore more about these neural pathways and the mechanisms underlying feeding behaviors. On a broader scale, these findings can inform future therapeutics that could help prevent unhealthy eating habits and obesity.

Effects of chronic high fat diet on mediobasal hypothalamic satiety neuron function in POMC-Cre mice

ObjectiveThe prevalence of obesity has increased over the past three decades. Proopiomelanocortin (POMC) neurons in the hypothalamic arcuate nucleus (ARC) play a vital role in induction of satiety. Chronic consumption of high-fat diet is known to reduce hypothalamic neuronal sensitivity to hormones like leptin, thus contributing to the development and persistence of obesity. The functional and morphological effects of a high-calorie diet on POMC neurons and how these effects contribute to the development and maintenance of the obese phenotype are not fully understood. For this purpose, POMC-Cre transgenic mice model was exposed to high-fat diet (HFD) and at the end of a 3- and 6-month period, electrophysiological and morphological changes, and the role of POMC neurons in homeostatic nutrition and their response to leptin were thoroughly investigated. MethodsEffects of HFD on POMC-satiety neurons in transgenic mice models exposed to chronic high-fat diet were investigated using electrophysiological (patch-clamp), chemogenetic and Cre recombinase advanced technological methods. Leptin, glucose and lipid profiles were determined and analyzed. ResultsIn mice exposed to a high-fat diet for 6 months, no significant changes in POMC dendritic spine number or projection density from POMC neurons to the paraventricular hypothalamus (PVN), lateral hypothalamus (LH), and bed nucleus stria terminalis (BNST) were observed. It was revealed that leptin hormone did not change the electrophysiological activities of POMC neurons in mice fed with HFD for 6 months. In addition, chemogenetic stimulation of POMC neurons increased HFD consumption. In the 3-month HFD-fed group, POMC activation induced an orexigenic response in mice, whereas switching to a standard diet was found to abolish orexigenic behavior in POMC mice. ConclusionsChronic high fat consumption disrupts the regulation of POMC neuron activation by leptin. Altered POMC neuron activation abolished the neuron's characteristic behavioral anorexigenic response. Change in nutritional content contributes to the reorganization of developing maladaptations.

A Neural Circuit from the Paraventricular Thalamus to the Bed Nucleus of the Stria Terminalis for the Regulation of States of Consciousness during Sevoflurane Anesthesia in Mice.

The neural circuitry underlying sevoflurane-induced modulation of consciousness is poorly understood. This study hypothesized that the paraventricular thalamus bed nucleus of the stria terminalis pathway plays an important role in regulating states of consciousness during sevoflurane anesthesia. Rabies virus-based transsynaptic tracing techniques were employed to reveal the neural pathway from the paraventricular thalamus to the bed nucleus of the stria terminalis. This study investigated the role of this pathway in sevoflurane anesthesia induction, maintenance, and emergence using chemogenetic and optogenetic methods combined with cortical electroencephalogram recordings. Both male and female mice were used in this study. Both γ-aminobutyric acid-mediated and glutamatergic neurons in the bed nucleus of the stria terminalis receive paraventricular thalamus glutamatergic projections. Chemogenetic inhibition of paraventricular thalamus glutamatergic neurons prolonged the sevoflurane anesthesia emergence time (mean ± SD, hM4D-clozapine N-oxide vs. mCherry-clozapine N-oxide, 281 ± 88 vs. 172 ± 48 s, P < 0.001, n = 24) and decreased the induction time (101 ± 32 vs. 136 ± 34 s, P = 0.002, n = 24), as well as the EC5 0 for the loss or recovery of the righting reflex under sevoflurane anesthesia (mean [95% CI] for the concentration at which 50% of the mice lost their righting reflex, 1.16 [1.12 to 1.20] vs. 1.49 [1.46 to 1.53] vol%, P < 0.001, n = 20; and for the concentration at which 50% of the mice recovered their righting reflex, 0.95 [0.86 to 1.03] vs. 1.34 [1.29 to 1.40] vol%, P < 0.001, n = 20). Similar results were observed during suppression of the paraventricular thalamus bed nucleus-stria terminalis pathway. Optogenetic activation of this pathway produced the opposite effects. Additionally, transient stimulation of this pathway efficiently induced behavioral arousal during continuous steady-state general anesthesia with sevoflurane and reduced the depth of anesthesia during sevoflurane-induced burst suppression. In mice, axonal projections from the paraventricular thalamic neurons to the bed nucleus of the stria terminalis contribute to regulating states of consciousness during sevoflurane anesthesia.

Tractography of the stria terminalis in the human brain.

The aim of this study was to investigate the trajectory of the stria terminalis and develop a protocol for mapping the stria terminalis using multi-shell diffusion images based tractography. The stria terminalis was reconstructed by combining one region of interest at the amygdala with another region of interest at the bed nucleus of stria terminalis. In addition, one region of avoidance was placed on the fornix at the interventricular foramen and another was set at the anterior perforated substance. The fiber-tracking protocol was tested in a Human Connectome Project-842 template, 35 healthy subjects from Massachusetts General Hospital, and 20 healthy subjects from the Human Connectome Project using generalized q-sampling imaging based tractography. The stria terminalis was reconstructed in the Human Connectome Project-842 template, 35 Massachusetts General Hospital healthy subjects, and 20 Human Connectome Project healthy subjects with our protocol. The stria terminalis originated from the amygdala and traveled parallel to the fornix. Then, the stria terminalis followed a C-shaped trajectory around the inferior, posterior, and dorsal surfaces of the thalamus before projecting to the bed nucleus of stria terminalis between the thalamus and caudate nucleus. There were no significant differences in the quantitative anisotropy and fractional anisotropy values between the left and right stria terminalis. The stria terminalis was accurately visualized across subjects using multi-shell diffusion images through generalized q-sampling imaging based tractography. This method could be an important tool for the reconstruction and evaluation of the stria terminalis in various neurological disorders. One Sentence Summary The visualization of the stria terminalis through the multi-shell diffusion images using generalized q-sampling imaging based tractography.

グルタミン酸受容体GluD1は高次脳機能領域に強く発現し、小脳では平行線維－プルキンエ細胞シナプスの形成に関与する

Of the two members of the δ subfamily of ionotropic glutamate receptors, GluD2 is exclusively expressed at parallel fiber-Purkinje cell (PF-PC) synapses in the cerebellum, and regulates their structural and functional connectivity. However, little is known to date regarding cellular and synaptic expression of GluD1 and its role in synaptic circuit formation. In the present study, we investigated this issue by producing specific and sensitive histochemical probes for GluD1 and analyzing cerebellar synaptic circuits in GluD1-knockout mice. GluD1 was widely expressed in the adult mouse brain, with high levels in higher brain regions, including the cerebral cortex, striatum, limbic regions (hippocampus, nucleus accumbens, lateral septum, bed nucleus stria terminalis, lateral habenula, and central nucleus of the amygdala), and cerebellar cortex. In the cerebellar cortex, GluD1 mRNA was expressed at the highest level in molecular layer interneurons, and its immunoreactivity was concentrated at PF synapses on interneuron somata. In GluD1-knockout mice, the density of PF synapses on interneuron somata was significantly reduced, and the size and number of interneurons were significantly diminished. Thus, GluD1 is common to GluD2 in expression at PF synapses, but distinct from GluD2 in neuronal expression in the cerebellar cortex, i,e., GluD1 in interneurons and GluD2 in PCs. Furthermore, GluD1 regulates the connectivity of PF-interneuron synapses, and promotes the differentiation and/or survival of molecular layer interneurons. These results suggest that GluD1 works in concert with GluD2 for the construction of cerebellar synaptic wiring through distinct neuronal and synaptic expressions and also their shared synapse-connecting function.

Artificial Intelligence Identified Resilient and Vulnerable Female Rats After Traumatic Stress and Ethanol Exposure: Investigation of Neuropeptide Y Pathway Regulation.

Post-traumatic stress disorder (PTSD) is initiated by traumatic-stress exposure and manifests into a collection of symptoms including increased anxiety, sleep disturbances, enhanced response to triggers, and increased sympathetic nervous system arousal. PTSD is highly co-occurring with alcohol use disorder. Only some individuals experiencing traumatic stress develop PTSD and a subset of individuals with PTSD develop co-occurring alcohol use disorder. To investigate the basis of these individual responses to traumatic stress, single prolonged stress (SPS) a rodent model of traumatic stress was applied to young adult female rats. Individual responses to SPS were characterized by measuring anxiety-like behaviors with open field and elevated plus maze tests. Rats were then allowed to drink ethanol under an intermittent two bottle choice procedure for 8 weeks, and ethanol consumption was measured. An artificial intelligence algorithm was built to predict resilient and vulnerable individuals based on data from anxiety testing and ethanol consumption. This model was implemented in a second cohort of rats that underwent SPS without ethanol drinking to identify resilient and vulnerable individuals for further study. Analysis of neuropeptide Y (NPY) levels and expression of its receptors Y1R and Y2R mRNA in the central nucleus of the amygdala (CeA), basolateral amygdala (BLA), and bed nucleus stria terminalis (BNST) were performed. Results demonstrate that resilient rats had higher expression of Y2R mRNA in the CeA compared with vulnerable and control rats and had higher levels of NPY protein in the BNST compared to controls. The results of the study show that an artificial intelligence algorithm can identify individual differences in response to traumatic stress which can be used to predict subsequent ethanol drinking, and the NPY pathway is differentially altered following traumatic stress exposure in resilient and vulnerable populations. Understanding neurochemical alterations following traumatic-stress exposure is critical in developing prevention strategies for the vulnerable phenotype and will help further development of novel therapeutic approaches for individuals suffering from PTSD and at risk for alcohol use disorder.

Effects of caffeine on ethanol-elicited place preference, place aversion and ERK phosphorylation in CD-1 mice.

Epidemiological studies indicate a rise in the combined consumption of caffeinated and alcoholic beverages, which can lead to increased risk of alcoholic-beverage overconsumption. However, the effects of the combination of caffeine and ethanol in animal models related to aspects of drug addiction are still underexplored. To characterize the pharmacological interaction between caffeine and ethanol and establish if caffeine can affect the ability of ethanol (2 g/kg) to elicit conditioned place preference and conditioned place aversion, we administered caffeine (3 or 15 mg/kg) to male CD-1 mice before saline or ethanol. Moreover, we determined if these doses of caffeine could affect ethanol (2 g/kg) elicited extracellular signal-regulated kinase phosphorylation in brain areas, nucleus accumbens, bed nucleus of stria terminalis, central nucleus of the amygdala, and basolateral amygdala, previously associated with this type of associative learning. In the place-conditioning paradigm, caffeine did not have an effect on its own, whereas ethanol elicited significant conditioned-place preference and conditioned-place aversion. Caffeine (15 mg/kg) significantly prevented the acquisition of ethanol-elicited conditioned-place preference and, at both doses, also prevented the acquisition of ethanol-elicited conditioned-place aversion. Moreover, both doses of caffeine also prevented ethanol-elicited extracellular signal-regulated kinase phosphorylation expression in all brain areas examined. The present data indicate a functional antagonistic action of caffeine and ethanol on associative learning and extracellular signal-regulated kinase phosphorylation after an acute interaction. These results could provide exciting grounds for further studies, also in a translational perspective, of their pharmacological interaction modulating other processes involved in drug consumption and addiction.

Functional deletion of neuropeptide Y receptors type 2 in local synaptic networks of anteroventral BNST facilitates recall and increases return of fear

Return of previously extinguished fear memories presents a major hurdle in treatment of fear-related disorders. Neuropeptide Y receptors type 2 (Y2R) in the bed nucleus of stria terminalis (BNST) seem to play a crucial role in modulation of remote fear memories. Here, we targeted Cre-channelrhodopsin-2 to defined subregions of BNST or central amygdala (CeA) in floxed Y2R mice (Y2lox/lox) for functional deletion of Y2R. We combined fear training and behavioral studies in vivo with optogenetic-electrophysiological analysis of BNST synaptic network activity ex vivo, in order to identify regional and cellular specificities of Y2R influence. Deletion of Y2R in the ventral section of anterior BNST (BNSTav) did not affect fear acquisition, but increased conditioned fear during recall and extinction learning, and aggravated remote fear return. By contrast, deletion of Y2R in the dorsal section of anterior BNST (BNSTad) or CeA did not influence acquisition, extinction or return of fear memories. Ex vivo optogenetic-electrophysiological analysis revealed Y2R-expressing local GABAergic inhibitory networks in BNST, both within (intraregional) and in-between (inter-regional) BNST subregions. Stimulation of Y2R resulted in a presynaptically mediated reduction of GABAergic responses, which did not differ between intraregional but predominantly affected inter-regional connections from BNSTav to BNSTad. Moreover, deletion of Y2R decreased the excitation/inhibition balance in BNSTav neurons, suggesting a regulatory influence of endogenous NPY via intraregional GABAergic microcircuits. This study reveals Y2R within local GABAergic networks in BNST as key elements in facilitating extinction and reducing return of remote fear memories, suggesting a potential avenue for translational purposes.

Divergent Neural Pathways Emanating from the Lateral Parabrachial Nucleus Mediate Distinct Components of the Pain Response

The lateral parabrachial nucleus (lPBN) is a major target of spinal projection neurons conveying nociceptive input into supraspinal structures. However, the functional role of distinct lPBN efferents in diverse nocifensive responses have remained largely uncharacterized. Here we show that that the lPBN is required for escape behaviors and aversive learning to noxious stimulation. In addition, we find that two populations of efferent neurons from different regions of the lPBN collateralize to distinct targets. Activation of efferent projections to the ventromedial hypothalamus (VMH) or lateral periaqueductal gray (lPAG) drives escape behaviors, whereas activation of lPBN efferents to the bed nucleus stria terminalis (BNST) or central amygdala (CEA) generates an aversive memory. Finally, we provide evidence that dynorphin-expressing neurons, which span cytoarchitecturally distinct domains of the lPBN, are required for aversive learning.

Effects of neural estrogen receptor beta deletion on social and mood-related behaviors and underlying mechanisms in male mice

Estradiol derived from neural aromatization of testosterone plays a key role in the organization and activation of neural structures underlying male behaviors. This study evaluated the contribution of the estrogen receptor (ER) β in estradiol-induced modulation of social and mood-related behaviors by using mice lacking the ERβ gene in the nervous system. Mutant males exhibited reduced social interaction with same-sex congeners and impaired aggressive behavior. They also displayed increased locomotor activity, and reduced or unaffected anxiety-state level in three paradigms. However, when mice were exposed to unescapable stress in the forced swim and tail suspension tests, they spent more time immobile and a reduced time in swimming and climbing. These behavioral alterations were associated with unaffected circadian and restraint stress-induced corticosterone levels, and unchanged number of tryptophan hydroxylase 2-immunoreactive neurons in the dorsal raphe. By contrast, reduced mRNA levels of oxytocin and arginine-vasopressin were observed in the bed nucleus of stria terminalis, whereas no changes were detected in the hypothalamic paraventricular nucleus. The neural ERβ is thus involved to different extent levels in social and mood-related behaviors, with a particular action on oxytocin and arginine-vasopressin signaling pathways of the bed nucleus of stria terminalis, yet the involvement of other brain areas cannot be excluded.

Threat bias and resting state functional connectivity of the amygdala and bed nucleus stria terminalis

BackgroundPrevious research has distinguished the activations of the amygdala and bed nucleus of stria terminalis (BNST) during threat-related contingencies. However, how intrinsic connectivities of the amygdala and BNST relate to threat bias remains unclear. Here, we investigated how resting state functional connectivity (rsFC) of the amygdala and BNST in healthy controls (HC) and patients with anxiety-related disorders (PAD) associate with threat bias in a dot-probe task. MethodsImaging and behavioral data of 30 PAD and 83 HC were obtained from the Nathan Kline Institute - Rockland sample and processed according to published routines. All imaging results were evaluated at voxel p < 0.001 and cluster p < 0.05, FWE corrected in SPM. ResultsPAD and HC did not show differences in whole brain rsFC with either the amygdala or BNST. In linear regressions threat bias was positively correlated with amygdala-thalamus/anterior cingulate cortex (ACC) rsFC in HC but not PAD, and with BNST-caudate rsFC in PAD but not HC. Slope tests confirmed group differences in the correlations between threat bias and amygdala-thalamus/ACC as well as BNST-caudate rsFC. LimitationsAs only half of the patients included were diagnosed with comorbid anxiety, the current findings need to be considered with the clinical heterogeneity and require replication in populations specifically with anxiety disorders. ConclusionsTogether, these results suggest amygdala and BNST connectivities as new neural markers of anxiety disorders. Whereas amygdala-thalamus/ACC rsFC support adaptive regulation of threat response in the HC, BNST-caudate rsFC may reflect maladaptive neural processes that are dominated by anticipatory anxiety.

The Role of the Basolateral Amygdala Projections to the Bed Nucleus of the Stria Terminalis in Anxiety‐like Behaviors in Male and Female Rats

Men and women display different symptomology in anxiety disorders, yet our understanding of the sex differences in the neurobiology related to these disorders is limited. The basolateral amygdala (BLA) is a critical component of the neurocircuitry involved in anxiety, is hyperactive in patients with anxiety disorders and displays a sexual dimorphism with respect to neural activity. Differences in BLA activity may be a contributing factor to sex differences in the pathophysiology of anxiety disorders. Prior studies have demonstrated that sex differences in BLA neuronal activity exist; however, it is not known whether specific subsets of BLA neurons exhibit this disparity. BLA outputs to the lateral bed nucleus stria terminalis (BSTL) play a critical role in the expression of prolonged cued fear and general anxiety‐like behavior with female rats expressing less general anxiety‐like behaviors compared to males. The purpose of this study was to determine if BLA‐BSTL neurons in female rats are less active than in males. We utilized in vivo single‐unit extracellular electrophysiological recordings to record anti‐dromically identified BLA‐BSTL neurons in anesthetized male and cycling female rats. We found that BLA‐BSTL neurons in females have lower firing frequencies compared to males, despite females having greater spontaneous BLA neuronal activity overall. We also examined whether prolonged cued fear conditioning, which is dependent, in part, on BLA‐BSTL connections, is less robust in female rats compared to males. Rats were conditioned to an 8 min tone, during which footshocks (0.3mA) were delivered at random. Four days later (when females were in the same estrous stage as training), rats were tested in a novel context and time spent freezing during the presentation of the tone was measured. No sex differences were observed during training, but proestrous females froze less during training compared to males and metestrous females. However, during extinction, females extinguished freezing behavior more quickly than males, and proestrous females froze less than metestrous females. To determine if our electrophysiological data suggesting decreased BLA‐BSTL activity in females leads to a decreased freezing behavior during prolonged cued fear, we utilized a chemogenic approach to selectively inhibit BLA‐BSTL neurons. We performed bilateral Cre‐dependent designer receptor exclusively activated by designer drug (DREADD) injections then assessed anxiety‐like behavior and freezing responses during prolonged cued fear. Preliminary results suggest that inhibition of BLA‐BSTL neurons during the open field task has opposite effects in male and female rats. Specifically, we found that BLA‐BSTL inhibition reduced latency to enter the center in males, but increased latency to enter center in females. Together this suggests that in addition to BLA‐BSTL neurons displaying sex differences in activity, these same neurons may also mediate different behaviors in male and female rats. These results may help explain the apparent disconnect between overall sex differences in BLA neuronal firing and its relation to particular anxiety behaviors.Support or Funding InformationR01MH100536This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The anxiolytic effects of Bai Le Mian capsule, a traditional Chinese hypnotic in mice

Bai Le Mian capsule (BLMC), which is composed of fifteen kinds of traditional Chinese Medicine, is a popular traditional Chinese medicine for the treatment of insomnia with anxiety. This study was to investigate the anxiolytic effect of BLMC in mice. BLMC (81, 162, and 325 mg/kg, i.g.) was given once or consecutively for 2 weeks, and anxiety behaviors were tested by the elevated plus maze, open field, and light/dark box, in normal mice and anxious model mice by meta-chlorophenyl-piperazine, a compound with known anxiogenic actions. In normal mice, single administration of BLMC at 325 mg/kg prolonged the time spent in central area by 2.1-fold in open-field test. Repeated administration once a day for 2 weeks, BLMC at 325 mg/kg increased the time spent in central area, open arms and light box by 2.8-, 2.0-, and 1.7-fold, respectively. Similarly, in anxious model mice, single treatment of BLMC at 325 mg/kg increased more time in the open arms by 2.1-fold. Consecutive administration for 2 weeks, BLMC at 325 mg/kg increased the time spent in open arms and light box by 2.3- and 2.1-fold. Immunohistochemical study showed that mCPP increased c-Fos expression in the central nucleus of the amygdala and bed nucleus of stria terminalis by 57% and 60%, and the mCPP-induced c-Fos expression could be reversed by single administration of BLMC. These results indicate that BLMC is an effective treatment for anxiety in mice.

Blockade of orexin receptors in the bed nucleus of stria terminalis increases serotonin level only in the left hypothalamus

The aim of investigation was to study the role of the hypothalamic serotoninergic system in mechanisms of blocking action of the orexin receptor antagonist on amphetamine-induced self-stimulation in rats. Methods. 27 male Wistar rats weighing 250-300 g were the object of the investigation. One week before the experiment, the microelectrodes were implanted into the lateral hypothalamus for self-stimulation and microcannulas into the bad nucleus of stria terminalis (BNST) for microinjections. The electrodes were implanted bilaterally and cannulas unilaterally (right or left). Intact rats and rats treated with amphetamine were controls. On the day of the experiment, amphetamine 1 mg/kg i.p. was injected, and then SB-408124 1 µg in 1 µl was administered into the BNST in 10 min. The rats were decapitated in 15 min after microinjection of SB-408124. The level of serotonin (Ser) and its metabolite 5-HIAA was determined in the right and the left hypothalamus by HPLC with electrochemical detection. Results. In intact rats, the 5-HIAA level in the left hypothalamus was higher than in the right one (p &lt; 0.05). After systemic administration of amphetamine the ratio of 5-HIAA/Ser was significantly decreased both in the left (p &lt; 0.05) and the right (p &lt; 0.05) hypothalamus. The levels of Ser and 5-HIAA stated symmetrical. It is important that effects of orexin antagonist after amphetamine administration appeared only on the side contralateral to microinjection being significantly only in the left hypothalamus. After administration of orexin antagonist into the right BNST, the level of Ser in the left hypothalamus increased compared both to intact rats (p &lt; 0.05) and rats treated with amphetamine (p &lt; 0.05). Conclusion. The results suggest that the left hypothalamus plays a leading role in developing of self-stimulation reaction and support the hypothesis that the serotoninergic system is involved in mechanism of blocking action of orexin receptors antagonist on self-stimulation activated with amphetamine. (For citation: Karpova IV, Bychkov ER, Lebedev AA, Shabanov PD. Blockade of orexin receptors in the bed nucleus of stria terminalis increases serotonin level only in the left hypothalamus. Reviews on Clinical Pharmacology and Drug Therapy. 2018;16(2):33-36. doi: 10.17816/RCF16233-36).

In Vitro Neurochemical Assessment of Methylphenidate and Its "Legal High" Analogs 3,4-CTMP and Ethylphenidate in Rat Nucleus Accumbens and Bed Nucleus of the Stria Terminalis.

3,4-dichloromethylphenidate (3,4-CTMP) and ethylphenidate are new psychoactive substances and analogs of the attention deficit medication methylphenidate. Both drugs have been reported on online user fora to induce effects similar to cocaine. In the UK, 3,4-CTMP appeared on the drug market in 2013 and ethylphenidate has been sold since 2010. We aimed to explore the neurochemical effects of these drugs on brain dopamine and noradrenaline efflux. 3,4-CTMP and ethylphenidate, purchased from online vendors, were analyzed using gas chromatography and mass spectroscopy to confirm their identity. Drugs were then tested in adolescent male rat brain slices of the nucleus accumbens and stria terminalis for effects on dopamine and noradrenaline efflux respectively. Fast cyclic voltammetry was used to measure transmitter release. Methylphenidate (10 μM) increased evoked dopamine and noradrenaline efflux by 4- and 2-fold, respectively. 3,4-CTMP (0.1 and 1 μM) increased evoked dopamine and noradrenaline efflux by ~6-fold and 2-fold, respectively. Ethylphenidate (1 μM) doubled evoked dopamine and noradrenaline efflux in both cases. 3,4-CTMP's effect on dopamine efflux was greater than that of methylphenidate, but ethylphenidate appears to be a weaker dopamine transporter inhibitor. Experiments using the dopamine D2 antagonist haloperidol, the noradrenaline α2 receptor antagonist yohimbine, the dopamine transporter inhibitor GBR12909 and the noradrenaline transporter inhibitor desipramine confirmed that we were measuring dopamine in the accumbens and noradrenaline in the ventral BNST. All three psychostimulant drugs, through their effects on dopamine efflux, may have addictive liability although the effect of 3,4-CTMP on dopamine suggests that it might be most addictive and ethylphenidate least addictive.

INTERACTION BETWEEN OREXIN AND OPIOIDS SYSTEMS OF THE STRUCTURES OF PARAAMYGDALAR COMPLEX IN THE REINFORCING EFFECTS OF SPONTANEOUS AND ACTIVATED SELF-STIMULATION OF THE LATERAL HYPOTHALAMUS

Male Wistar rats were implanted bipolar electrodes into the lateral hypothalamus to study self-stimulation reaction in the Skinner box and microcannulas into the right lateral ventricle and structutes of the paraamygdalar complex (bed nucleus of stria terminalis, central nucleus of amygdala or nucleus accumbens) to study central effects of orexin (5 µg in 5 µl i. v. for an injection) on the reinforcing properties of pharmacological drugs. Intraperitoneal administration of trimeperidine (3 mg/kg), a synthetic opioid, was shown to increase self-stimulation of the lateral hypothalamus in the Skinner box (number of pedal pressings for 10 min) by 51.8%, and sulpiride (5 mg/kg, a small dose), an antagonist of D2 dopamine receptors, did not change but in the large dose (20 mg/kg) decreased self-stimulation by 49.3% (a number of pedal pressings, or self-stimulation frequency within 10 min). At the same time, SB-408124, an antagonist of OX1R receptors and its combination with orexin did not change self-stimulation indexes after intrastructural administration into the bed nucleus of stria terminalis, central nucleus of amygdala or nucleus accumbens. On the background of blockade of OX1R receptors by SB-408124 (1 µg for all structures) trimeperidine reduced their activating action on self-stimulation reaction. Sulpiride (5 mg/kg i. p., a dose not affecting self-stimulation reaction) blocked activating action of trimeperidine after blockade OX1R receptors by SB-408124 (1 µg). The data obtained can suggest that OX1R receptors participate in the reinforcing effects of synthetic opioid trimeperidine and the blockade of them by SB-408124 potentiate antagonist effects of sulpiride on self-stimulation (4 tables, bibliography: 23 refs).

P.1.g.045 - Endocannabinoid neurotransmission inhibits the formation of nitric oxide in the bed nucleus stria terminalis during acute restraint stress in rats

To date, although some microRNAs (miRNAs) have been discovered in the holometabolism insect Tribolium castaneum, large numbers of miRNAs still require investigation. Knocking down Dicer-1 (Dcr-1) and Argonaute-1 (Ago-1) in late larvae impaired miRNA synthesis, affected the juvenile hormone pathway by up-regulating Methoprene-tolerant (Met) and Krüppel-homolog1 (Kr-h1) transcript levels, and resulted in a series of defects in T. castaneum development and metamorphosis. Thus, high-throughput Illumina/Solexa sequencing was performed with a mixed sample of eight key developmental stages of T. castaneum. In total, 1154 unique miRNAs were discovered containing 274 conserved miRNAs belong to 68 miRNA families, 108 known candidate miRNAs and 772 novel miRNAs. Genome locus analysis showed that miRNA clusters are more abundant in T. castaneum than other species. The results indicated that RNAi of Dcr-1 and Ago-1 in T. castaneum resulted in miRNA-induced metamorphosis defects. Furthermore, large numbers of novel miRNAs were discovered in T. castaneum and localized to T. castaneum genome loci.

Genetic divergence in the transcriptional engram of chronic alcohol abuse: A laser-capture RNA-seq study of the mouse mesocorticolimbic system.

Genetic factors that influence the transition from initial drinking to dependence remain enigmatic. Recent studies have leveraged chronic intermittent ethanol (CIE) paradigms to measure changes in brain gene expression in a single strain at 0, 8, 72h, and even 7 days following CIE. We extend these findings using LCM RNA-seq to profile expression in 11 brain regions in two inbred strains - C57BL/6J (B6) and DBA/2J (D2) - 72h following multiple cycles of ethanol self-administration and CIE. Linear models identified differential expression based on treatment, region, strain, or interactions with treatment. Nearly 40% of genes showed a robust effect (FDR<0.01) of region, and hippocampus CA1, cortex, bed nucleus stria terminalis, and nucleus accumbens core had the highest number of differentially expressed genes after treatment. Another 8% of differentially expressed genes demonstrated a robust effect of strain. As expected, based on similar studies in B6, treatment had a much smaller impact on expression; only 72 genes (p<0.01) are modulated by treatment (independent of region or strain). Strikingly, many more genes (415) show a strain-specific and largely opposite response to treatment and are enriched in processes related to RNA metabolism, transcription factor activity, and mitochondrial function. Over 3 times as many changes in gene expression were detected in D2 compared to B6, and weighted gene co-expression network analysis (WGCNA) module comparison identified more modules enriched for treatment effects in D2. Substantial strain differences exist in the temporal pattern of transcriptional neuroadaptation to CIE, and these may drive individual differences in risk of addiction following excessive alcohol consumption.

Multiple amygdaloid divisions of arcopallium send convergent projections to the nucleus accumbens and neighboring subpallial amygdala regions in the domestic chicken: a selective pathway tracing and reconstruction study

Retrograde tracing with choleratoxin B, injected into the nucleus accumbens (Ac) and bed nucleus of stria terminalis, lateral part (BSTL), yielded labeled perikarya in a ring-shaped area of arcopallium, including dorsal and hilar subdivisions, with a wedge-shaped node of dense accumulation in the amygdalopiriform area (APir). Also, the position of source neurons for this arcopallio-subpallial pathway was verified by anterograde tracing. Three subregions of arcopallium (amygdalopiriform, dorsal, hilar) were injected with dextran (10 kDa), and fibers and terminal fields were detected in Ac, BSTL and extended amygdala (EA). Most abundant projections to Ac arose from APir. The study enabled precise description of the main output fiber streams: the dorsal stream follows the dorsal border of arcopallium and, continuing in the ventral amygdalofugal tract, it traverses the EA and the BSTL before reaching the Ac. The ventral stream of fibers enters the EA along the ventral subpallial border and terminates in the basal nucleus and ventral pallidum. The course of the pathway was reconstructed in 3D. Retrogradely labeled arcopallial neurons were devoid of DARPP-32. DARPP-32 was present in the Ac but not the BSTL. No colocalization between the calcium binding proteins calbindin, parvalbumin and calretinin, and retrogradely labeled neurons was detected, despite a considerable territorial overlap. This finding further supports the excitatory nature of the arcopallial-accumbens pathway. Conjoint and convergent amygdalar input to EA, including BSTL, as well as to Ac subregions likely transmits fear and aggression related signals to both viscerolimbic (EA) and learned reward- and motivation-related (Ac) ventrobasal forebrain regions.

Stress increases GABAergic neurotransmission in CRF neurons of the central amygdala and bed nucleus stria terminalis

Corticotrophin Releasing Factor (CRF) is a critical stress-related neuropeptide in major output pathways of the amygdala, including the central nucleus (CeA), and in a key projection target of the CeA, the bed nucleus of the stria terminalis (BnST). While progress has been made in understanding the contributions and characteristics of CRF as a neuropeptide in rodent behavior, little attention has been committed to determine the properties and synaptic physiology of specific populations of CRF-expressing (CRF+) and non-expressing (CRF−) neurons in the CeA and BnST. Here, we fill this gap by electrophysiologically characterizing distinct neuronal subtypes in CeA and BnST. Crossing tdTomato or channelrhodopsin-2 (ChR2-YFP) reporter mice to those expressing Cre-recombinase under the CRF promoter allowed us to identify and manipulate CRF+ and CRF− neurons in CeA and BnST, the two largest areas with fluorescently labeled neurons in these mice. We optogenetically activated CRF+ neurons to elicit action potentials or synaptic responses in CRF+ and CRF− neurons. We found that GABA is the predominant co-transmitter in CRF+ neurons within the CeA and BnST. CRF+ neurons are highly interconnected with CRF− neurons and to a lesser extent with CRF+ neurons. CRF+ and CRF− neurons differentially express tonic GABA currents. Chronic, unpredictable stress increase the amplitude of evoked IPSCs and connectivity between CRF+ neurons, but not between CRF+ and CRF− neurons in both regions. We propose that reciprocal inhibition of interconnected neurons controls CRF+ output in these nuclei.