Dorsomedial Part Research Articles

Morphological and Histological Studies of the Bronchial and Parabronchial System of the White Pekin Duck (Anas platyrhynchos).

The present study aimed to provide comprehensive morphological features of the bronchial and parabronchial systems using cast, histological, histochemical, and scanning electron microscopy techniques, with new insights into the parabronchial topographic distribution system on 22 white Pekin ducks. Casting illustrated that the medioventral secondary bronchi (MVSB) were the largest, but the posterior (POSB) ones were the smallest. The primary (PB) and secondary bronchi (SB) were lined with thin pseudostratified, ciliated columnar epithelium. PB contained discontinuous hyaline cartilage plates interconnected by a membrane of fibrous CT with chondrocytes, while SB had mucous glands. There were two types of hexagonal parabronchi with different lumen shapes: circular in neopulmonic and longitudinal in paleopulmonic. The parabronchi had numerous atria opened into the lumen and guarded by different directed muscles: horizontal in the neopulmonic and vertical or horizontal in the paleopulmonic. The atria were lined with squamous to cuboidal cells, forming the interatrial septum (IAS). A funnel atrial duct connecting the atrium to the infundibulum can be branched. The air capillaries were nearby, at a very short distance from the blood capillaries. Despite their small number, air capillaries, which were found in parabronchi, significantly increased in size and diameter. SEM at the 4th torus level showed a parabronchi distribution with elongated paleopulmonic on the dorsomedial part, hexagonal neopulmonic on the ventrolateral part, and some neopulmonic on the medial part. The parabronchial topography distribution exhibited their unique distribution from the 1st to the 6th torus level.

Orexin-A attenuated motion sickness through modulating neural activity in hypothalamus nuclei.

We evaluated the hypothesis that central orexin application could counteract motion sickness responses through regulating neural activity in target brain areas. Thec effects of intracerebroventricular (i.c.v.) injection of orexin-A and SB-334867 (OX1 antagonist) on motion sickness-induced anorexia, nausea-like behaviour (conditioned gaping), hypoactivity and hypothermia were investigated in rats subjected to Ferris wheel-like rotation. Orexin-A responsive brain areas were identified using Fos immunolabelling and were verified via motion sickness responses after intranucleus injection of orexin-A, SB-334867 and TCS-OX2-29 (OX2 antagonist). The efficacy of intranasal application of orexin-A versus scopolamine on motion sickness symptoms in cats was also investigated. Orexin-A (i.c.v.) dose-dependently attenuated motion sickness-related behavioural responses and hypothermia. Fos expression was inhibited in the ventral part of the dorsomedial hypothalamus (DMV) and the paraventricular nucleus (PVN), but was enhanced in the ventral part of the premammillary nucleus ventral part (PMV) by orexin-A (20 μg) in rotated animals. Motion sickness responses were differentially inhibited by orexin-A injection into the DMV (anorexia and hypoactivity), the PVN (conditioned gaping) and the PMV (hypothermia). SB-334867 and TCS-OX2-29 (i.c.v. and intranucleus injection) inhibited behavioural and thermal effects of orexin-A. Orexin-A (60 μg·kg-1) and scopolamine inhibited rotation-induced emesis and non-retching/vomiting symptoms, while orexin-A also attenuated anorexia with mild salivation in motion sickness cats. Orexin-A might relieve motion sickness through acting on OX1 and OX2 receptors in various hypothalamus nuclei. Intranasal orexin-A could be a potential strategy against motion sickness.

VMHdm/cSF-1 neuronal circuits regulate skeletal muscle PGC1-α via the sympathoadrenal drive

ObjectiveTo adapt to metabolically challenging environments, the central nervous system (CNS) orchestrates metabolism of peripheral organs including skeletal muscle. The organ-communication between the CNS and skeletal muscle has been investigated, yet our understanding of the neuronal pathway from the CNS to skeletal muscle is still limited. Neurons in the dorsomedial and central parts of the ventromedial hypothalamic nucleus (VMHdm/c) expressing steroidogenic factor-1 (VMHdm/cSF-1 neurons) are key for metabolic adaptations to exercise, including increased basal metabolic rate and skeletal muscle mass in mice. However, the mechanisms by which VMHdm/cSF-1 neurons regulate skeletal muscle function remain unclear. Here, we show that VMHdm/cSF-1 neurons increase the sympathoadrenal activity and regulate skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) in mice via multiple downstream nodes. MethodsOptogenetics was used to specifically manipulate VMHdm/cSF-1 neurons combined with genetically-engineered mice and surgical manipulation of the sympathoadrenal activity. ResultsOptogenetic activation of VMHdm/cSF-1 neurons dramatically elevates mRNA levels of skeletal muscle Pgc-1α, which regulates a spectrum of skeletal muscle function including protein synthesis and metabolism. Mechanistically, the sympathoadrenal drive coupled with β2 adrenergic receptor (β2AdR) is essential for VMHdm/cSF-1 neurons-mediated increases in skeletal muscle PGC1-α. Specifically, both adrenalectomy and β2AdR knockout block augmented skeletal muscle PGC1-α by VMHdm/cSF-1 neuronal activation. Optogenetic functional mapping reveals that downstream nodes of VMHdm/cSF-1 neurons are functionally redundant to increase circulating epinephrine and skeletal muscle PGC1-α. ConclusionsCollectively, we propose that VMHdm/cSF-1 neurons-skeletal muscle pathway, VMHdm/cSF-1 neurons→multiple downstream nodes→the adrenal gland→skeletal muscle β2AdR, underlies augmented skeletal muscle function for metabolic adaptations.

Subcutaneous Implantation of Unidirectional Self-Inflating Anisotropic Tissue Expander Has No Effect on the Physiological Parameters and Behaviours of Horses

The tissue expansion technique is one of the most important innovations in skin reconstructive surgery in human and veterinary medicine. This study investigated horses’ physiological and behavioural responses to subcutaneous implantation of a unidirectional self-inflating anisotropic tissue expander. The tissue expanders were subcutaneously implanted on six horses at three different locations: the frontal region of the head, the lateral side of the right shoulder, and the dorsomedial part of the cannon region of the right forelimb. Prior to the tissue expander implantation, each horse was clinically examined, and the observed vital parameters and behaviour were recorded as baseline data. For six days post implantations, the horses were clinically examined, implantation sites monitored, and the horse’s behaviour was recorded both during the day by visual observation and at night with a video camera. The results showed that all horses tolerated the subcutaneous gradual skin expansion by implantation of the tissue expanders, and all surgical sites healed without any complications. The implantation of the tissue expanders does not affect the vital parameters or overall horse behaviour either during the day or at night. In conclusion, the subcutaneous implantation of unidirectional anisotropic tissue expanders in horses resulted in successful skin growth with no physiological and psychological discomfort; hence skin expansion is a good option to be considered when pursuing equine skin reconstructive surgery.

An Insula-Enriched Regulator of Retinoic Acid Marks a New Intersection in the Neural Circuitry of Mouse Social Behavior

An Insula-Enriched Regulator of Retinoic Acid Marks a New Intersection in the Neural Circuitry of Mouse Social Behavior

Activation of the VpdmVGLUT1-VPM pathway contributes to anxiety-like behaviors induced by malocclusion.

Occlusal disharmony has a negative impact on emotion. The mesencephalic trigeminal nucleus (Vme) neurons are the primary afferent nuclei that convey proprioceptive information from proprioceptors and low-threshold mechanoreceptors in the periodontal ligament and jaw muscles in the cranio-oro-facial regions. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) and the ventral posteromedial nucleus (VPM) of thalamus have been proven to be crucial relay stations in ascending pathway of proprioception. The VPM sends numerous projections to primary somatosensory areas (SI), which modulate emotion processing. The present study aimed to demonstrate the ascending trigeminal-thalamic-cortex pathway which would mediate malocclusion-induced negative emotion. Unilateral anterior crossbite (UAC) model created by disturbing the dental occlusion was applied. Tract-tracing techniques were used to identify the existence of Vme-Vpdm-VPM pathway and Vpdm-VPM-SI pathway. Chemogenetic and optogenetic methods were taken to modulate the activation of VpdmVGLUT1 neurons and the Vpdm-VPM pathway. Morphological evidence indicated the involvement of the Vme-Vpdm-VPM pathway, Vpdm-VPM-SI pathway and VpdmVGLUT1-VPM pathway in orofacial proprioception in wild-type mice and vesicular glutamate transporter 1 (VGLUT1): tdTomato mice, respectively. Furthermore, chemogenetic inhibition of VpdmVGLUT1 neurons and the Vpdm-VPM pathway alleviated anxiety-like behaviors in a unilateral anterior crossbite (UAC) model, whereas chemogenetic activation induced anxiety-like behaviors in controls and did not aggravate these behaviors in UAC mice. Finally, optogenetic inhibition of the VpdmVGLUT1-VPM pathway in VGLUT1-IRES-Cre mice reversed UAC-induced anxiety comorbidity. In conclusion, these results suggest that the VpdmVGLUT1-VPM neural pathway participates in the modulation of malocclusion-induced anxiety comorbidity. These findings provide new insights into the links between occlusion and emotion and deepen our understanding of the impact of occlusal disharmony on brain dysfunction.

PACAP-PAC1R modulates fear extinction via the ventromedial hypothalamus

Exposure to traumatic stress can lead to fear dysregulation, which has been associated with posttraumatic stress disorder (PTSD). Previous work showed that a polymorphism in the PACAP-PAC1R (pituitary adenylate cyclase-activating polypeptide) system is associated with PTSD risk in women, and PACAP (ADCYAP1)-PAC1R (ADCYAP1R1) are highly expressed in the hypothalamus. Here, we show that female mice subjected to acute stress immobilization (IMO) have fear extinction impairments related to Adcyap1 and Adcyap1r1 mRNA upregulation in the hypothalamus, PACAP-c-Fos downregulation in the Medial Amygdala (MeA), and PACAP-FosB/ΔFosB upregulation in the Ventromedial Hypothalamus dorsomedial part (VMHdm). DREADD-mediated inhibition of MeA neurons projecting to the VMHdm during IMO rescues both PACAP upregulation in VMHdm and the fear extinction impairment. We also found that women with the risk genotype of ADCYAP1R1 rs2267735 polymorphism have impaired fear extinction.

The role of PACAP/PAC1R in PTSD: effects on fear extinction via the ventromedial hypothalamus

Introduction The incidence and severity of posttraumatic stress disorder (PTSD) is higher in women than men because of environmental and biological factors. Specific mechanisms in the PACAP-PAC1R (pituitary adenylate cyclase-activating polypeptide and its type I receptor) system may confer PTSD risk in women. Interestingly, while the PACAP (ADCYAP1) - PAC1R (ADCYAP1R1) system is expressed highly in the hypothalamus, no relationship has been described for this pathway in the hypothalamus with fear processing or in PTSD.ObjectivesWe studied whether the estrous/menstrual cycle at the moment of trauma predicts PTSD and the involvement of the PACAP neurons in the amygdala and hypothalamus during traumatic stress.MethodsMice: DREADDs, immunohistochemistry and behavior. Humans: fear-potentiated startle and questionnaires.Results Here, we show that acute stress immobilization (IMO) produces fear extinction impairments in female mice. Also, IMO elicits Adcyap1 and Adcyap1r1 mRNA upregulation in the hypothalamus, PACAP/c-Fos downregulation in the medial amygdala (MeA), and PACAP/FosB/ΔFosB upregulation in the ventromedial hypothalamus dorsomedial part (VMHdm) after fear extinction. We also found that women with the risk genotype of ADCYAP1R1 rs2267735 SNP show impaired fear extinction. In mice, DREADD-mediated inhibition of the MeA neurons projecting to the VMHdm during IMO rescues both PACAP upregulation in VMHdm and the fear extinction impairment. We ruled out contributions from inherent hormonal states showing that the menstrual or estrous cycle phase at the moment of trauma does not result in a vulnerable phenotype.ConclusionsOur data suggest that the PACAP-PAC1R hypothalamic system may be a novel candidate to treat and prevent PTSD symptoms including fear dysregulations.DisclosureNo significant relationships.

An interesting sexually dimorphic species, Chamobates callipygis Pavlichenko, 1991 (Acari, Oribatida, Chamobatidae), with remarks on sexual dimorphism in Ceratozetoidea.

Based on materials from the leaf litter of a mixed forest in Crimea, a new diagnosis for the sexually dimorphic species, Chamobates callipygis Pavlichenko, 1991, is presented to accommodate its previously unreported females. This is the only species in Chamobatidae showing a distinct sexual dimorphism, which is expressed by the posterior porose region on the notogaster, such that males only have a large protuberance on the posterior part of notogaster bearing a pair of fused porose areas A3, and a densely striated region behind them. The specific function of this structure is not yet known, but the sexual dimorphism is presumably involved in pheromonal communication facilitating sperm transfer. Also, the males of this species have a few transverse striations in the dorsomedial part of notogaster (at level of porose areas A1 and A2). Further, we discuss all cases of sexual dimorphism in the superfamily Ceratozetoidea, and the possible function of this dimorphism.

Evaluation of immunoreactive for glial fibrillary acidic protein astrocytes in the periaqueductal gray matter of rats treated with monosodium glutamate.

The aim of this study was to evaluate the glial fibrillary acidic protein immunoreactive (GFAP-IR) astrocytes in the periaqueductal gray matter (PAG) of rats treated with monosodium glutamate (MSG). This study was performed on PAG sections of rats treated subcutaneously with MSG (2 g/kg b.w. (group I) and 4 g/kg b.w. (group II)) and saline (group C). Immunohistochemical reactions were performed by peroxidase-antiperoxidase method using an antibody against GFAP protein. In animals receiving MSG in dorsomedial (dm) and dorsolateral (dl) parts of PAG the majority of astrocytes had GFAP-IR bodies and few thin, poorly branched protuberances. In lateral (l) and ventrolateral (vl) parts of PAG cells with numerous, branched protuberances with GFAP expression were observed. Some astrocytes in vl PAG of group II rats were characterized by strongly stained cytoplasmic bodies and thick, multiple branched protuberances. Statistically significant differences in the number of GFAP-IR astrocytes were shown between control animals and group II in dm PAG and dl PAG. All MSG-treated animals revealed statistically significantly fewer immunonegative structures for GFAP as well as all cells in the PAG.In the PAG of rats receiving MSG, especially at high dose, there is an increase in GFAP immunoreactivity in astrocytes. The hypertrophy of GFAP-IR cells and the probable lack of their proliferation may indicate isomorphic astroglia in response to increased extracellular glutamate concentrations. However, the decrease in their number in dm PAG and dl PAG may be related to MSG cytotoxicity.

The effect of opioid promoting social behavior is negatively regulated by the activity of dorsomedial part of periaqueductal grey

The effect of opioid promoting social behavior is negatively regulated by the activity of dorsomedial part of periaqueductal grey

A self-powered closed-loop brain-machine-interface system for real-time detecting and rapidly adjusting blood glucose concentration

The traditional methods of detecting and adjusting blood glucose concentration, such as blood analysis and insulin injection, may delay the treatment of metabolic disease. Here, a new self-powered closed-loop brain-machine-interface system for real-time detecting and rapidly adjusting blood glucose concentration has been fabricated. The system can work without external power supply and be self-powered by the body motion itself, which can meet the requirement of immediate treatment. The system mainly consists of active blood glucose sensor, energy harvester, micro-control unit and brain stimulator. The blood glucose sensor made of enzyme/ZnO nanowire arrays can output piezoelectric voltage under the driving of body motion, and the output can be treated as the glucose-detecting signal through the biosensing-piezoelectric coupling effect. A piezoelectric ceramic device as the energy harvester can convert the body mechanical energy into electricity for powering the whole system. The micro-control unit outputs brain stimulation pulse to the dorsomedial part of the ventromedial hypothalamus (VMHdm) in the brain upon abnormal blood glucose concentration. In mouse samples, the brain stimulator connected to the VMHdm augments the expression of regulatory nerve receptors to achieve rapid increase of blood glucose concentration (39% within 10 min). Thus, a closed loop is formed among the body, brain and system. This self-powered closed-loop approach improves the accessibility of physiological insights and extends brain-machine-interface application in precision medicine for metabolic diseases.

MK-801-induced behavioral and dopaminergic responses in the shell part of the nucleus accumbens in adult male rats are disrupted after neonatal blockade of the ventral subiculum

The present study was conducted in the context of animal modeling of schizophrenia. It investigated in adult male rats, after transient neonatal blockade of the ventral subiculum (VSub), the impact of a very specific non-competitive antagonist of NMDA receptors (MK-801) on locomotor activity and dopaminergic (DAergic) responses in the dorsomedial shell part of the nucleus accumbens (Nacc), a striatal subregion described as the common target region for antipsychotics.The functional neonatal inactivation of the VSub was achieved by local microinjection of tetrodotoxin (TTX) at postnatal day 8 (PND8). Control pups were microinjected with the solvent phosphate buffered saline (PBS). Locomotor responses and DAergic variations in the dorsomedial shell part of the Nacc were measured simultaneously using in vivo voltammetry in awake, freely moving male animals after sc administration of MK-801. The following results were obtained: 1) a dose-dependent increase in locomotor activity in PBS and TTX animals, greater in TTX rats/PBS rats; and 2) divergent DAergic responses for PBS and TTX animals. A decrease in DA levels with a return to around basal values was observed in PBS animals. An increase in DA levels was obtained in TTX animals. The present data suggest that neonatal blockade of the VSub results in disruption in NMDA glutamatergic transmission, causing a disturbance in DA release in the dorsomedial shell in adults male rats. In the context of animal modeling of schizophrenia using the same approach it would be interesting to investigate possible changes in postsynaptic NMDA receptors-related proteins in the dorsomedial shell region in the Nacc.

Gamma Oscillations and Coherence Are Weaker in the Dorsomedial Subregion of STN in Parkinson's Disease.

Background: Deep-brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for motor symptoms of advanced Parkinson's disease (PD). Due to a lack of detailed somatotopic organization in STN, the clinically most effective part of the STN for stimulation has already become one of the hot research focuses. At present, there are some reports about topographic distribution for different depths within the STN, but few about a mediolateral topography in this area.Objective: The objective was to investigate the local field potential (LFP) distribution patterns in dorsomedial and dorsolateral subparts of STN.Methods: In total, 18 PD patients eventually enrolled in this study. The DBS electrodes were initially located on the lateral portion of dorsolateral STN. Because of internal capsule side effects presented at low threshold (below 1.5 mA), the electrode was reimplanted more medially to the dorsomedial STN. In this process, intraoperative LFPs from dorsomedial and dorsolateral STN were recorded from the inserted electrode. Both beta power and gamma power of the LFPs were calculated using the power spectral density (PSD) for each DBS contact pair. Furthermore, coherence between any two pairs of contacts was computed in the dorsomedial and dorsolateral parts of STN, respectively. Meanwhile, the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) was monitored prior to surgery and at the 6-month follow-up.Results: Compared to the dorsolateral part of STN, gamma oscillations (p < 0.01) and coherence (p < 0.05) were all weaker in the dorsomedial part. However, no obvious differences in beta oscillations and coherence were observed between the two groups (p > 0.05). Moreover, it should be noted that DBS of the dorsomedial STN resulted in significant improvement in the UPDRS-III in PD patients. There was a 61.50 ± 21.30% improvement in UPDRS-III scores in Med-off/Stim-on state relative to the Med-off state at baseline (from 15.44 ± 6.84 to 43.94 ± 15.79, p < 0.01).Conclusions: The specific features of gamma activity may be used to differentiate STN subregions. Moreover, the dorsomedial part of STN might be a potential target for DBS in PD.

Investigation of the neural correlates of mentalizing through the Dynamic Inference Task, a new naturalistic task of social cognition

Understanding others’ intentions requires both the identification of social cues (e.g., emotional facial expressions, gaze direction) and the attribution of a mental state to another. The neural substrates of these processes have often been studied separately, and results are heterogeneous, in part attributable to the variety of paradigms used. The aim of the present study was to explore the neural regions underlying these sociocognitive processes, using a novel naturalistic task in which participants engage with human protagonists featured in videos.A total of 51 right-handed volunteers underwent functional magnetic resonance imaging while performing the Dynamic Inference Task (DIT), manipulating the degree of inference (high vs. low), the presence of emotion (emotional vs. nonemotional), and gaze direction (direct vs. averted).High nonemotional inference elicited neural activation in temporal regions encompassing the right posterior superior temporal sulcus. The presence (vs. absence) of emotion in the high-inference condition elicited a bilateral pattern of activation in internal temporal areas around the amygdala and orbitofrontal structures, as well as activation in the right dorsomedial part of the superior frontal gyrus and the left precuneus.On account of its dynamic, naturalistic approach, the DIT seems a suitable task for exploring social interactions and the way we interact with others, both in nonclinical and clinical populations.

New faunistical and taxonomic data on oribatid mites of the superfamily Plateremaeoidea (Acari, Oribatida) of Bolivia

Two new species of the superfamily Plateremaeoidea (Acari, Oribatida) belonging to the genera Pheroliodes (Licnodamaeidae) and Plateremaeus (Plateremaeidae) are described from Bolivia. Both families as well as one known species (Plateremaeus ornatissimus) are recorded in the Bolivian fauna for the first time. Adult of Ph. bolivianus sp. nov. is similar to Ph. barringtonensis in main traits (e.g., notogaster with small, widely spaced foveolae; some notogastral setae phylliform; bothridial seta comparatively long, clavate), but differs from the latter by the smaller body length, the presence of broadly phylliform setae lp, h1 and p1 and setiform setae p2 and p3, and by a large number of transverse ridges and furrows in dorsomedial part on the prodorsum. Adult of Pl. yurtaevi sp. nov. differs from all other species of the genus by the presence of clavate bothridial seta and distantly inserted adanal seta ad3 from anal aperture. The tritonymphal instar of Ph. bolivianus sp. nov. is compared to those of the other species.

The myth that psychotherapy is more effective than pharmacotherapy in anxiety disorders

The specific role of the striatum, especially its dorsolateral (DLS) and dorsomedial (DMS) parts, in male copulatory behavior is still debated. In order to clarify their contribution to male sexual behavior, we specifically ablated the major striatal neuronal subpopulations, direct and indirect medium spiny neurons (dMSNs and iMSNs) in DMS or DLS, and dMSNs, iMSNs and cholinergic interneurons in nucleus accumbens (NAc),The main results of this study can be summarized as follows:In DMS, dMSN ablation causes a reduction in the percent of mice that mount a receptive female, and a complex alteration in the parameters of the copulatory performance, that is largely opposite to the alterations induced by iMSN ablation.In DLS, dMSN ablation causes a widespread alteration in the copulatory behavior parameters, that tends to disappear at repetition of the test; iMSN ablation induces minor copulatory behavior alterations that are complementary to those observed after dMSN ablation.In NAc, dMSN ablation causes a marked reduction in the percent of mice that mount a receptive female and a disruption of copulatory behavior, while iMSN ablation induces minor copulatory behavior alterations that are opposite to those observed with dMSN ablation, and cholinergic neuron ablation induces a selective decrease in mount latency.Overall, present data point to a complex region and cell-specific contribution to copulatory behavior of the different neuronal subpopulations of both dorsal and ventral striatum, with a prominent role of the dMSNs of the different subregions.

Effect of dental malocclusion on cerebellar neuron activation via the dorsomedial part of the principal sensory trigeminal nucleus

Occlusion has been proposed to play a role for body posture and balance, both of which are mediated mainly by the cerebellum. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) has direct projection to the cerebellum. The experimental unilateral anterior crossbite (UAC) has an impact on the motor nuclei in the brain stem via trigeminal mesencephalic nucleus (Vme). The current aim was to explore whether UAC has an impact on Vpdm‐cerebellum circuit. The inferior alveolar nerve was injected into cholera toxin B subunit (CTb), the cerebellum was injected into fluoro‐gold (FG), and the Vpdm was injected into biotinylated dextran amine (BDA) to identify the activation of Vpdm‐cerebellum circuit by UAC. Data indicated that there were more neuronal nuclei (NeuN)/CTb/FG triple‐labelled neurons and NeuN/CTb/vesicular glutamate transporter 1(VGLUT1) triple‐labelled neurons in the Vpdm, and more NeuN/BDA/ VGLUT1 triple‐labelled neurons in the cerebellum of rats with UAC than in control rats. The VGLUT1 expression in the Vpdm and cerebellum in the UAC group was higher than that in control rats. These findings indicate an excitatory impact of UAC on the Vpdm‐cerebellum pathway and support the role of occlusion for body posture and balance.

Dorsal and ventral striatal neuronal subpopulations differentially disrupt male mouse copulatory behavior

The specific role of the striatum, especially its dorsolateral (DLS) and dorsomedial (DMS) parts, in male copulatory behavior is still debated. In order to clarify their contribution to male sexual behavior, we specifically ablated the major striatal neuronal subpopulations, direct and indirect medium spiny neurons (dMSNs and iMSNs) in DMS or DLS, and dMSNs, iMSNs and cholinergic interneurons in nucleus accumbens (NAc),The main results of this study can be summarized as follows:In DMS, dMSN ablation causes a reduction in the percent of mice that mount a receptive female, and a complex alteration in the parameters of the copulatory performance, that is largely opposite to the alterations induced by iMSN ablation.In DLS, dMSN ablation causes a widespread alteration in the copulatory behavior parameters, that tends to disappear at repetition of the test; iMSN ablation induces minor copulatory behavior alterations that are complementary to those observed after dMSN ablation.In NAc, dMSN ablation causes a marked reduction in the percent of mice that mount a receptive female and a disruption of copulatory behavior, while iMSN ablation induces minor copulatory behavior alterations that are opposite to those observed with dMSN ablation, and cholinergic neuron ablation induces a selective decrease in mount latency.Overall, present data point to a complex region and cell-specific contribution to copulatory behavior of the different neuronal subpopulations of both dorsal and ventral striatum, with a prominent role of the dMSNs of the different subregions.

Changes in the Expression of Steroidogenic Factor 1 (SF-1) in Neurons in the Ventromedial Nucleus of the Hypothalamus in Rats on Aging

Expression of steroidogenic factor 1 in neurons in the ventromedial nucleus of the hypothalamus in rats was studied using an immunohistochemical method and western blotting in young (2–3 months) and aged (2–2.5 years) male and female rats. Steroidogenic factor 1 was present in a majority of neurons in the ventromedial nucleus of the hypothalamus in young and aged rats, in the dorsomedial part of the nucleus. In aged rats, the proportion of neurons immunoreactive to steroidogenic factor 1 decreased significantly, from 88% to 68% in males and from 82 to 66% in females. There were no significant sex-related differences in the numbers of immunopositive neurons in either age group. Expression of steroidogenic factor 1 was also significantly lower in aged male and female rats in terms of western blot results. Thus, aging was associated with changes in the neurochemical composition of the ventromedial nucleus of the hypothalamus, which is involved in regulating energy metabolism and sexual behavior.