Reticular System Research Articles

Origin of biancane and calanchi in East Aliano, southern Italy

Areas underlain by Plio-Pleistocene marine mudstone in south Italy are severely affected by denudation processes and have been transformed into badlands with two well defined types of landform: biancane and calanchi. In this paper, factors that contributed to the development of the Aliano badlands and particularly to the geneses of biancane and calanchi have been studied, based on aerospace data; field observations on geomorphic processes and geological structure; laboratory measurements of soil and bedrock samples; and morphometric analysis. Several maps and spatial data were prepared to describe factors which are thought to be related with landform formations, such as lineament distribution, elevation, slope, and pipe distribution. Morphometric characteristics of biancane and calanchi (steepness and slope length), dominant active processes, and the dip/orientation of beddings, joints, and fault planes were investigated, and 71 samples of soils and bedrock were taken to characterise their properties. The results of the analyses of the soil/bedrock samples show no significant differences in their properties between biancane and calanchi. Field observations do not support the idea that biancane are the final product of calanchi development, but support the hypothesis that biancane and calanchi are formed under different terrain conditions related to structural patterns and denudation processes of highly erodible materials. The origin of biancane is associated with highly dissected surfaces along a reticular system of small joints. In contrast, calanchi are formed on steep wall-like slopes along larger lineaments where the rate of incision into the slopes surpasses the denudation of the densely vegetated back-slope.

Characterization of Hemodynamic Events Following Intravascular Infusion of Recombinant Adenovirus Reveals Possible Solutions for Mitigating Cardiovascular Responses

Intravascular administration of recombinant adenovirus (rAd) in cancer patients has been well tolerated. However, dose-limiting hemodynamic responses associated with suppression of cardiac output have been observed at doses of 7.5 x 10(13) particles. While analysis of hemodynamic responses induced by small-molecule pharmaceuticals is well established, little is known about the cardiovascular effects of rAd. Telemetric cardiovascular (CV) monitoring in mice was utilized to measure hemodynamic events following intravascular rAd administration. Electrocardiogram analysis revealed a block in the SA node 3-4 min postinfusion, resulting in secondary pacemaking initiated at the AV node. This was associated with acute bradycardia, reduced blood pressure, and hypothermia followed by gradual recovery. Adenovirus-primed murine sera with high neutralizing antibody (nAb) titers could inhibit CV responses, whereas human sera with equivalent nAb titers induced by natural infection were, surprisingly, not inhibitory. Interestingly, repeat dosing within 2-4 h of the primary injection resulted in desensitization, resembling tachyphylaxis, for subsequent CV responses. Last, depletion of Kupffer cells prior to rAd infusion precluded induction of CV responses. These inhibitory effects suggest that rAd interactions with certain cells of the reticular endothelial system are associated with induction of CV responses. Significantly, these studies may provide insight into management of acute adverse effects following rAd systemic delivery, enabling a broadening of therapeutic index.

La tuberculose splénique pseudotumorale isolée. (À propos d'un cas)

The tuberculosis isolated tumoral spleen is rare, even in the countries to strong tubercular endemic. From an observation, concerning an important, tumoral and isolated splenomegaly in 48-year-old-man. The authors put the accent on his tumorous variety by the clinic, the imagery and on macroscopic appearance of the operative piece. Are discussed the isolated character, the way of dissemination, the site of initial infestation and the deceitful character of haematological manifestations. A splenectomy to diagnostic and therapeutic goal have been realised, associated to the chemotherapy. This is an expression of the profound organ's tuberculosis rich on endothelial reticular system. It's mean a singular topography of the bacillary lesion and a great distribution of the tubercular affect.

Clinicopathological Characterization of Monkey B Virus ( Cercopithecine Herpesvirus 1) Infection in Mice

The purpose of this study was to establish a small animal model for monkey B virus (BV) infection. Mice were inoculated intramuscularly with several BV isolates. Comparisons were based upon the doses required to produce infection (ID50), non-central nervous system (CNS) clinical disease (CS50), CNS disease (CNSD50) and lethal effect (LD50). Strains differed in respect of the dose required to produce clinical disease in BALB/c mice. C57BL/6 mice were more resistant than BALB/c mice to CNS disease. Skin lesions at the inoculation site consisted of epidermal necrosis, ulceration, serocellular crusts and underlying dermatitis. CNS lesions included marked inflammation in the ipsilateral dorsal root ganglion and lumbar spinal cord (point of viral entry). The distribution of the lumbar spinal cord lesions suggested viral entry via sensory afferent neurons, ventral motor tracts, or both. The lesions in the more cranial spinal cord segments suggested ascension to the brain via bilateral spinothalamic and spinoreticular tracts. Brain lesions included encephalitis with neuronal necrosis and white matter destruction located consistently at the base of the brainstem, the reticular system, and rostrally to the thalamus and hypothalamus. Viral antigen was detected immunohistochemically in the lesions. The results indicated an ascending encephalomyelitis syndrome similar to that produced by BV in man.

Nuclear RNAs confined to a reticular compartment between chromosome territories

RNA polymerase II transcripts are confined to nuclear compartments. A detailed analysis of the nuclear topology of RNA from individual genes was performed for transcripts from the marker gene coding for chloramphenicol acetyltransferase, expressed at a high level from the HTLV-1 LTR promoter. The construct was transfected into A293 cells where the RNA was organized as an extensive reticular network. We also studied the RNA distribution from combinations of neighboring HIV and bacterial resistance genes that co-integrated within the genome of COS-7 cells—revealing spherical or track-like accumulations of RNA that were extensively branched. There were many nuclei with distinct but overlapping RNA accumulations. Since the coding genes localized at the overlapping points, the RNAs are synthesized at a common region and diverge. The correlation between the frequency of the separation of the transcripts and the physical distance of the respective genes suggests a subcompartmentalization in the microenvironment of genes on the basis of geometric parameters. Thus, the more distant the genes are on the same chromosome, the more likely they are confined to separated subcompartments of an extensive reticular system. Co-delineation of the RNA transcripts with Cajal bodies and chromosome territories indicated the organization of nuclear RNA transcripts in a reticular interchromosome domain compartment.

Predominance of clockwise swimming during rest in Southern Hemisphere dolphins

Observations on eight bottlenose dolphins located in the Southern Hemisphere during rest indicated that they spent the majority of the time (85%) engaged in behaviors that can be considered clockwise. This is in contrast with many observations of sleeping/resting dolphins in the Northern Hemisphere that spend the majority of their time involved in counterclockwise activity. This observation leads to the possibility that the reason for preferential swimming biases in dolphins is the result of global forces rather than the result of the anatomy of the individual dolphins. Our observations also indicate that dolphins change overt behavior every 40 s, coincident with the respiration rate. The possibility is suggested that the salience of neural activity controlling respiration in the reticular system may effect/disrupt reticular attentional mechanisms, thus leading to the changes in overt behavior. It is hypothesized that this 40-s period may represent the possible attention span of the sleeping bottlenose dolphin.

Specific Deficits of Saccadic Eye Movements after Sleep Deprivation

Sleep deprivation (SD) and reduced vigilance impair not only the performance of cognitive tasks, but also of saccadic eye movements. Previous literature reports reduced peak velocities and prolonged latencies of visually-guided saccades, but the latter remained controversial. To clarify which specific saccadic subfunctions reflect reduced vigilance, we investigated the effect of a one-night SD on 3 different types of saccades that are controlled by different cortical networks: 1) visually-guided pro-saccades controlled more by the parietal (PEF) than by the frontal eye field (FEF; 2) anti-saccades (performed into the direction opposite to a peripheral target, with respect to the vertical meridian), controlled by FEF, the dorsolateral prefrontal cortex (DLPFC), and the basal ganglia loop; 3) memory-guided saccades (performed to a peripheral target that had been flashed 1 to 30s before), controlled by the PEF, the FEF, the supplementary eye field (SEF), the DLPFC and the basal ganglia loop. Eye movements were recorded using EOG in 15 healthy adults at 3 different times: in the evening prior to SD (baseline), in the next morning following a one night's SD (day 1), and 24 hours later (day 2), following a night of sufficient sleep. A control group of 15 healthy adults was tested similarly, but without SD. Results showed specific effects of SD only on day 1, that had recovered completely on day 2 and were not found in the control group: 1) reduced peak velocities of all 3 types of saccades, indicating dysfunction of the paramedian pontine reticular formation (PPRF), which is part of the ascending reticular system involved in sleep-wake regulation; 2) prolonged latencies only of memory-guided saccades, but normal metrics, reflecting impaired initiation of voluntary saccades. Due to their long memorization times of up to 30s they had to be initiated almost like self-paced saccades which are controlled by the SEF. 3) Dysmetria (mainly hypometria) of visually-guided saccades, indicating rather a cerebellar dysfunction, as the essential functions of the PEF (latency of visually-guided saccades and metrics of memory-guided saccades) and of the FEF (error rate and latency of anti-saccades) were not affected. We conclude that sleep deprivation and reduced vigilance cause dysfunction of specific brain areas, such as the SEF, the cerebellum, and the PPRF, whereas other areas were not affected, particularly the primary frontal and parietal eye fields.

Intrauterine Cerebral Processing of External Vibroacoustic Stimuli

The human and the sheep fetus, the animal model of human pregnancy, respond to external stimuli such as vibrations or noises with behavior state changes from 0.8 gestation onwards. It is not clear yet 1) if the behavior state changes that represent a „subcortical“ arousal are accompanied by a „cortical“ arousal as a condition of conscious perception of the stimuli; 2) to what extent the perception of the stimuli depends on the behavior state and the quality of the stimulus; and 3) if the proprioceptive system is important for perception of the vibratory component of the signal. Via Cesarean section, sheep fetuses were chronically instrumented at 0.8 gestation with ECoG (electrocorticogram) electrodes as well as EOG, EMG and EKG electrodes to define fetal behavior states. After a recovery period of five days, stimuli were presented from the abdominal wall of the ewe during periods of NREM and REM sleep. We tested pure vibratory (30min) and acoustic (5h) stimuli as well as dynamic amplitude and frequency modulated and two static vibroacoustic stimuli (VAS) produced by an electronic artificial larynx (EAL) and a laboratory shaker. ECoG changes were analyzed using linear (power spectral analysis) and non-linear methods. For non-linear analysis we used an algorithm based on the Wolf algorithm (calculation of the leading Lyapunov exponent) which calculates a point prediction error (PE) regarding the course of the time series in the phase space. The vibratory and acoustic stimuli did not induce a cortical arousal. The VAS produced an arousal with similar effectiveness during NREM and REM sleep. The dynamic stimulus induced 100%, the EAL 70% and the laboratory shaker 40–50% responses. The PE showed a high predictability in NREM and a low predictability of the ECoG in REM sleep. Although the power spectrum differed between VAS in NREM (decrease of delta activity) and REM sleep (beta activation), the PE showed that the cortical activation pattern did not depend on the sleep state and the stimulus. Processes of cortical activation and deactivation during spontaneous sleep state changes and VAS were similar in their time courses. Cochlear ablation prevented from arousal, suggesting that stimuli were detected through the auditory rather than the proprioceptive system. The results show that external VAS induce a cortical arousal during the last trimester depending on the stimulus. The time course of cortical activation within 32s suggests an arousal via the ascending activating reticular system rather than via specific fiber systems.

L’affectivité dans le système nerveux

Affectivity is an ambiguous term, related altogether to, mood, well-being, ill-being, emotional states, and at the same time to individual sensitivity, capacity to feel moved, as well as feelings and passions. We want to show that those states, as different as they may seem, belong to the perception by the central nervous system of past or present modifications, of an organism reacting to situations it has to cope with. Opposite to common opinion, this affectivity is not "generated" by the cerebral cortex but by the central brain. It results from memory input by the limbic system and from information processing by the hypothalamus and the reticular system, and from processing of mood and emotional rates provoked by self reactions in order to perpetuate survival, protection or one's own species. Considered as "favourable" or "unfavourable" after analyses by the limbic cortex, those states become in the central brain "pleasure" or "aversion", and generate motivation for action, to follow-on or to stop. From the limbic cortex, those motivations are transmitted to the contiguous prefrontal cortex. The prefrontal cortex is a center for action imitation. One may imagine it as a center for conscious cortical activity and for affective memory. This organisation of affectivity and affective memory settings in 2 different centers and at two different levels of the nervous system: the limbic cortex and the prefrontal neo-cortex. The prefrontal neo-cortex only is conscious, but the limbic cortex, although unconscious, is a source of motivation. One is led to describe an unconscious affectivity. It is impossible to talk about this affectivity without mentioning Freud's unconscious.

Regional brainstem expression of Fos associated with sexual behavior in male rats

This study utilized Fos expression to map the distribution of activated cells in brainstem areas following masculine sexual behavior. Males displaying both appetitive and consumatory sexual behaviors (Cop) were compared to animals prevented from copulation (NC) and to socially isolated (SI) animals. Following copulation, Fos was preferentially augmented in the caudal ventral medulla (CVM), a region mediating descending inhibition of penile reflexes, and which may be regulated by a forebrain circuit that includes the medial preoptic area (MPOA). Copulation-induced Fos was observed in the medial divisions of both the dorsal cochlear nucleus (DC) and trapezoid bodies (Tz), areas which are part of a circuit processing auditory information. In addition, the medullary linear nucleus (Li) displayed comparable amounts of Fos in Cop and NC as compared to the SI animals. Other regions of the pontomedullary reticular system, which may mediate sleep and arousal, did not exhibit Fos expression associated with consumatory sexual behavior. We suggest that Fos is associated with the inhibition of sexual behavior following ejaculation in the CVM, and that auditory information arising from the DC and Tz is combined with copulation-related sensory information in the subparafasicular nucleus and projected to the hypothalamus. In addition, equal amounts of Fos expression observed in the Li in both the Cop and NC animals suggests that this region is involved in sexual arousal. Overall, the data suggest that processing by brainstem nuclei directly contributes to the regulation of mating behavior in male rats.

FLUORESCENT BERBERINE BINDING AS A MARKER OF INTERNAL GLYCOSAMINOGLYCANS SULFATE IN BOVINE OOCYTES AND SPERM CELLS

The use of berberine as a biological marker of glycosamineglycans sulfate was employed to corroborate the presence of heparin in mammalian oocytes and sperm and its distribution in all the structures, or only in some specialized zones, of the male and female gametes. Oocytes and sperms were treated with 1.8 mM berberine for the presence of heparin and examined 10, 30, 60, and 120 minutes later. We have found that heparin is homogeneously distributed in all the zones of bovine oocytes and in sperm cells. When sperm cells are first treated with 80 microM of heparin and then berberine, 40% of them display in their post acrosomal region an intense yellow fluorescence. This may be in relation to the high amount of heparin binding sites due to the presence of the reticular membranous like system in this sperm region and in its possible role whereby gametes recognize and adhere to one another. Therefore, the use of berberine as a fluorescent marker of heparin represents clear proof of the presence of GAGs and their binding sites in the outside and inside of mammalian gametes, reinforcing the importance they play in the events of the process of fertilization.

Gene expression in rat vestibular and reticular structures during and after space flight

Space flight produces profound changes of neuronal activity in the mammalian vestibular and reticular systems, affecting postural and motor functions. These changes are compensated over time by plastic alterations in the brain. Immediate early genes (IEGs) are useful indicators of both activity changes and neuronal plasticity. We studied the expression of two IEG protein products [Fos and Fos-related antigens (FRAs)] with different cell persistence times (hours and days, respectively) to identify brainstem vestibular and reticular structures involved in adaptation to microgravity and readaptation to 1 G (gravity) during the NASA Neurolab Mission (STS-90). IEG protein expression in flight animals was compared to that of ground controls using Fisher 344 rats killed 1 and 12 days after launch and 1 and 14 days after landing. An increase in the number of Fos-protein-positive cells in vestibular (especially medial and spinal) regions was observed 1 day after launch and 1 day after landing. Fos-positive cell numbers were no different from controls 12 days after launch or 14 days after landing. No G-related changes in IEG expression were observed in the lateral vestibular nucleus. The pattern of FRA protein expression was generally similar to that of Fos, except at 1 day after landing, when FRA-expressing cells were observed throughout the whole spinal vestibular nucleus, but only in the caudal part of the medial vestibular nucleus. Fos expression was found throughout the entire medial vestibular nucleus at this time. While both Fos and FRA expression patterns may reflect the increased G force experienced during take-off and landing, the Fos pattern may additionally reflect recent rebound episodes of rapid eye movement (REM) sleep following forced wakefulness, especially after landing. Pontine activity sources producing rhythmic discharges of vestibulo-oculomotor neurons during REM sleep could substitute for labyrinthine signals after exposure to microgravity, contributing to activity-related plastic changes leading to G readaptation. Reticular structures exhibited a contrasting pattern of changes in the numbers of Fos- and FRA-positive cells suggestive of a major influence from proprioceptive inputs, and plastic re-weighting of inputs after landing. Asymmetric induction of Fos and FRAs observed in some vestibular nuclei 1 day after landing suggests that activity asymmetries between bilateral otolith organs, their primary labyrinthine afferents, and vestibular nuclei may become unmasked during flight.

Surface membranes, Golgi complexes, and vacuolar systems.

In the absence of fossils, the cells of vertebrates are often described in lieu of a general animal eukaryote model, neglecting work on insects. However, a common ancestor is nearly a billion years in the past, making some vertebrate generalizations inappropriate for insects. For example, insect cells are adept at the cell remodeling needed for molting and metamorphosis, they have plasma membrane reticular systems and vacuolar ferritin, and their Golgi complexes continue to work during mitosis. This review stresses the ways that insect cells differ from those of vertebrates, summarizing the structure of surface membranes and vacuolar systems, especially of the epidermis and fat body, as a prerequisite for the molecular studies needed to understand cell function. The objective is to provide a structural base from which molecular biology can emerge from biochemical description into a useful analysis of function.

Alpha-tocopherol protects cultured human cells from the acute lethal cytotoxicity of dioxin.

The possible protection of cultured human cells from acute dioxin injury by antioxidants was investigated. The most potent dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), caused vacuolization of the smooth endoplasmic reticulum and Golgi apparatus in cultured human conjunctival epithelial cells and cervical cancer cells. Subsequent nuclear damage included a deep irregular indentation resulting in cell death. A dosage of 30-40 ng/mL TCDD induced maximal intracellular production of H2O2 at 30 minutes and led to severe cell death (0-31% survival) at two hours. A dose of 1.7 mM alpha-tocopherol or 1 mM L-dehydroascorbic acid significantly protected human cells against acute TCDD injuries (78-97% survivals), but vitamin C did not provide this protection. These results indicate that accidental exposure to fatal doses of TCDD causes cytoplasmic free radical production within the smooth endoplasmic reticular systems, resulting in severe cytotoxicity, and that vitamin E and dehydroascorbic acid can protect against TCDD-induced cell damage.

Peculiar aspects of reading and writing performances in patients with olivopontocerebellar atrophy.

Olivopontocerebellar atrophy (OPCA) is a still debated condition, of which motor disruption is the most common feature. A high incidence of associated mood disorders may exist, but there are few studies on concomitant cognitive impairment. Our aim was to assess whether there is reading and writing disruption in olivopontocerebellar atrophy (OPCA). 6 patients were administered different reading and writing tasks. Scores were then compared to those obtained by healthy volunteers. There was an evident impairment in reading and writing execution in our patients compared to those of the control group. On the contrary, no difference could be found in abstraction, problem-solving, and memory tasks. We discuss the results, debating the role of the cerebellum in the conscious process of cognition or in ocular movement control (necessary for reading and writing fluidity and effective execution) and in the dynamic activation of all the cerebral cortex mediated by the diffuse projection to the reticular system.

Anxiety and Related Factors in Chronic Pain

Clinicians often encounter patients who present with both chronic pain and elevated levels of anxiety. In some cases, the source of the anxiety is vague and diffuse. For others, there is an identifiable precipitating object, event or situation. For example, some patients with chronic pain are able to attribute their anxiety to the possibility of not regaining lost functional abilities, financial difficulties, feelings of social inadequacy, or uncertainty about the meaning and consequences of pain. The association between chronic pain and anxiety may not be particularly surprising when one considers that, in the acute phase, both pain and target‐oriented anxiety (or fear) motivate actions that serve to minimize the threat and maximize the likelihood of successful escape. As well, their neurobiology, while distinct, interacts in the reticular system (1). Evaluations of the association between chronic pain and fear‐relevant constructs were initiated in the 1960s and 1970s (2,3). It has only been of late, however, that theorists and researchers have begun to focus their attention on delineating the precise nature of the relationship and its specific implications for the assessment and management of pain.

Different myrosinase and idioblast distribution in Arabidopsis and Brassica napus.

Myrosinase (EC 3.2.3.1) is a glucosinolate-degrading enzyme mainly found in special idioblasts, myrosin cells, in Brassicaceae. This two-component system of secondary products and degradative enzymes is important in plant-insect interactions. Immunocytochemical analysis of Arabidopsis localized myrosinase exclusively to myrosin cells in the phloem parenchyma, whereas no myrosin cells were detected in the ground tissue. In Brassica napus, myrosinase could be detected in myrosin cells both in the phloem parenchyma and in the ground tissue. The myrosin cells were similar in Arabidopsis and B. napus and were found to be different from the companion cells and the glucosinolate-containing S-cells present in Arabidopsis. Confocal laser scanning immunomicroscopy analysis of myrosin cells in B. napus embryos showed that the myrosin grains constitute a continuous reticular system in the cell. These findings indicate that in the two species studied, initial cells creating the ground tissue have different potential for making idioblasts and suggest that the myrosinase-glucosinolate system has at least partly different functions. Several myrosinases in B. napus extracts are recovered in complex together with myrosinase-binding protein (MBP), and the localization of MBP was therefore studied in situ. The expression of MBP was highest in germinating seedlings of B. napus and was found in every cell except the myrosin cells of the ground tissue. Rapid disappearance of the MBP from the non-myrosin cells and emergence of MBP in the myrosin cells resulted in an apparent colocalization of MBP and myrosinase in 7-d-old seedlings.

The Sensory Canal Systems of the Living Coelacanth, Latimeria Chalumnae: A New Instalment

Entire sensory canal systems of the coelacanth, Latimeria chalumnae, are described: not only the course of principal canals with their primary and secondary collaterals, but also the course and branches of the pit-line and reticular canals. The number of pores on the left side of the head were found to be 296 in an early (yolksac) embryo, 321 in a late term fetus, 485 in a juvenile, and 2974 in adults. This means that in latimeria most of the lateral-line canal system develop after parturition. Pit lines of the living coelacanth are not rows of superficial neuromasts but canals covered by a thin epidermis like in other sensory canals of the lateral line. These pit-line canals, however, have a very specific structure and branching pattern: the medial dorsal pit-line canal is connected by fine branches on top of the head. The infra-dentary pit-line canal connects via these branches with canals deep inside the bones. Several fine and richly branched canaliculi of unknown function radiate from each quadratojugal pit-line canal. The gular plate pit-line canal has superficially branching arms as well as connections to numerous deeper canals inside the bone. These canals consist of fine branches that in turn lead to and open on the ventral surface of the gular plates as small pores. The system is reminiscent of the reticular (pore) canal system known only from some fossil agnathans and fishes. Thus latimeria combines the reticular system of ancient vertebrates with the lateral-line system of modern fishes. The significance of this gular (possibly electro-sensory) system for feeding by the coelacanth will be discussed.

Estudio electrofisiológico córtico­subcortical durante los efectos de benzodiacepinas en pacientes con trastornos de pánico

Tribute to Robert Heath, M.D. a pioneer in human implanted corticosubcortical microelectrodes. We evaluate retrospective electroencephalography (EEG), local evoked potentials (LEP) and extracellular unitary activity (EUA) of patients with diagnosis of panic disorder in association of simple partial seizures. These patients had presences or absence of agoraphobia. They received treatment with clonazepam or diazepam. Ten patients with implanted corticosubcortical were divided in two groups. The five patients of group A were treated with clonazepam and the five patients of group B with diazepam. Panic attacks showed EEG thetha activity, increased amplitude of the negative phase of LEP, and an increase in the frequency of EUA in cortico-subcortical organizations. This changes occurred in all organizations with exception of the inhibitory reticular substance. Panic disorder produced abundance of repetitive epileptiform discharges that could precipitate convulsive crisis. Both benzodiazepines were efficacious although results with clonazepam were observed earlier: at 7 to 14 days. Benzodiazepines increased corticosubcortical EEG beta activity, decreased amplitude of negative phase of LEP, and diminution in the frequency of EUA. This changes occurred with exception on the inhibitory reticular system. We postulate: a) That panic disorder hyperexcitability at the cortico-subcortical neuronal level may be the result of gabergic dysfunction, or alteration in neuroinhibitory mechanism through GABAA receptors, and through GABAB neuromodulator receptors, and b) That there is a direct correlation between GABA inhibitory basic mechanism and electroencephalographic beta activity. Panic disorder produces neuronal hyperexcitability by gabergic dysfunction both benzodiazepines were efficacious in treatment.

The cerebrocerebellar system: anatomic substrates of the cerebellar contribution to cognition and emotion

The contribution of the cerebellum to the modulation of cognition and emotion is facilitated by the connections between the cerebellum and brain structures known to be associated with a wide array of non-motor behaviors. The cerebellum has interconnections with brainstem and thalamic reticular systems that subserve arousal. Autonomic activity is supported by the reciprocal interconnections with the hypothalamus. Limbic and paralimbic connections include the hypothalamus, septal region, hippocampus,and cingulate gyrus. Associative connections consist of both feedforward and feedback limbs.The basilar pons receives inputs from the prefrontal, posterior parietal, superior temporal, parahippocampal, and cingulate cortices, as well as from the sensorimotor cortices. This information is conveyed from the pons to cerebellum, before it is relayed back via thalamus to the associative and paralimbic regions of the cerebral cortex. The anatomical arrangement of segregated loops of cerebral cortical connections stands in contrast to the cerebellar cortical architecture that is essentially uniform. This has theoretical and clinical ramifications. It is the anatomical basis for the dysmetria of thought hypothesis that postulates a universal cerebellar transform, in which the cerebellum performs its unique computation in a topographically precise manner on diverse streams of information relating to almost all aspects of behavior including cognition and emotion. It provides an anatomic basis for the observations of cerebellar activation by cognitive and affective paradigms in functional neuroimaging experiments. It helps explain the clinical phenomena that characterize the cerebellar cognitive affective syndrome, and it provides an anatomic basis for a causal relationship between cerebellar pathology and psychiatric and neurobehavioral conditions. Knowledge of these anatomical pathways is critical to the further development of hypotheses, experimental approaches, and clinical questions that can advance the understanding of the contribution of the cerebellum to cognition and to disorders of intellect and emotion.