Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

A model of the neuropsychology of anxiety is proposed. The model is based in the first instance upon an analysis of the behavioural effects of the antianxiety drugs (benzodiazepines, barbiturates, and alcohol) in animals. From such psychopharmacologi-cal experiments the concept of a “behavioural inhibition system” (BIS) has been developed. This system responds to novel stimuli or to those associated with punishment or nonreward by inhibiting ongoing behaviour and increasing arousal and attention to the environment. It is activity in the BIS that constitutes anxiety and that is reduced by antianxiety drugs. The effects of the antianxiety drugs in the brain also suggest hypotheses concerning the neural substrate of anxiety. Although the benzodiazepines and barbiturates facilitate the effects of γ-aminobutyrate, this is insufficient to explain their highly specific behavioural effects. Because of similarities between the behavioural effects of certain lesions and those of the antianxiety drugs, it is proposed that these drugs reduce anxiety by impairing the functioning of a widespread neural system including the septo-hippocampal system (SHS), the Papez circuit, the prefrontal cortex, and ascending monoaminergic and cholinergic pathways which innervate these forebrain structures. Analysis of the functions of this system (based on anatomical, physiological, and behavioural data) suggests that it acts as a comparator: it compares predicted to actual sensory events and activates the outputs of the BIS when there is a mismatch or when the predicted event is aversive. Suggestions are made as to the functions of particular pathways within this overall brain system. The resulting theory is applied to the symptoms and treatment of anxiety in man, its relations to depression, and the personality of individuals who are susceptible to anxiety or depression.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0140525X00013066

Précis of The Neuropsychology of Anxiety: An Enquiry into the Functions of the Septo-Hippocampal System..

Dementia prevention, intervention, and care

The ascending monoamine pathways in the rat brain are demonstrated by the pile up of fluorescent material occurring in the axons after various types of lesions. The anatomy of the pathways is outlined in drawings of frontal sections of the brain and the origin and termination of several pathways is determined by studying the anterograde and retrograde degeneration occurring after well localised lesions. It is possible to separate the ascending NA pathways into a dorsal and a ventral bundle of axons. The dorsal bundle innervates the cortex and the hippocampus and the ventral bundle supplies NA nerve terminals to the medulla, the pons, the mesencephalon and the diencephalon. The dorsal bundle is found to originate in the locus coeruleus. Lesions of this nucleus abolish the nerve terminals in all cortical areas and in several other areas of the brain indicating a unique role for the locus coeruleus in influencing the activity of the entire brain. The 5-HT pathways have a distribution similar to the ventral NA pathyway. The course of the nigro-striatal and the meso-limbic DA pathways is presented in detail.

Stereotaxic mapping of the monoamine pathways in the rat brain.

Interneurons of the hippocampus

Loss of a circadian adrenal corticosterone rhythm following suprachiasmatic lesions in the rat.

Reduced number of hypocretin neurons in human narcolepsy.

Suprachiasmatic nucleus : the mind's clock

A direct projection from the retina to the hypothalamus was demonstrated in the rat. Following injection of tritiated leucine or proline into the posterior chamber of the eye, labelled protein was shown autoradiographically in the suprachiasmatic nuclei of the medial hypothalamus, both ipsilateral and contralateral to the injected eye. The labelling of the nucleus was heaviest in its ventral portion but extended throughout the nucleus. No evidence for a projection to the supraoptic nucleus or any other hypothalamic nucleus was observed. All of the known terminal nuclei of the primary and accessory optic tracts were heavily labelled. The projection to the suprachiasmatic nucleus could not be clearly confirmed in material prepared using the Fink-Heimer method for the demonstration of degenerating axon terminals. Electron microscopic study of the suprachiasmatic nucleus following orbital enucleation showed degenerating endings making synaptic contacts with small dendrites of the suprachiasmatic nucleus cells. These first appeared at three days after operation and were nearly gone by seven days. Thus, the retinohypothalamic tract in the rat appears to arise from the ganglion cells of the retina and to terminate on the smaller dendritic branches of the neurons of the suprachiasmatic nucleus.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/cne.901460102

A retinohypothalamic projection in the rat

In this study the location of dopamine (DA) neuron perikarya in the rostral mesencephalon of the rat was determined using the glyoxylic acid fluorescence histochemical technique. Subsequently the topography of the projection of these mesencephalic neurons on the basal forebrain and striatum was analyzed using the anterograde transport-autoradiographic tracing method and the retrograde transport-horseradish peroxidase (HRP) technique. The results of these anatomical studies were correlated with the biochemical and histochemical studies presented in previous reports (Moore, 1978; Fallon and Moore, 1978; Fallon et al., 1978) to provide the following conclusions. The topography of the DA neuron projection on the basal forebrain and neostriatum is organized in three planes, dorsal-ventral, medial-lateral and anterior-posterior. DA cells are found almost exclusively in the substantia nigra (SN) and ventral tegmental area (VTA). Ventral cells of the SN and VTA project to the dorsal structures of the basal forebrain such as the septum, nucleus accumbens and neostriatum. The latter includes some DA cells located ventrally in the pars reticulata of the SN. Dorsal cells project to ventral structures. The medial-lateral topography is organized such that the medial sectors of the SN-VTA area project to the medial parts of nuclei in the basal forebrain and neostriatum whereas lateral sectors of the SN-VTA area project to the lateral parts of nuclei in the basal forebrain and neostriatum. An anterior-posterior topography also is evident such that anterior parts of the SN-VTA project anteriorly whereas the posterior SN-VTA projects more posteriorly in these areas. These observations are consistent with the view that the DA neurons of the SN-VTA complex form a single nuclear group with a highly topographically organized projection innervating not only deep nuclei of the telencephalon but allocortical structures as well.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/cne.901800310

Robert Y. Moore

Papers

Loss of a circadian adrenal corticosterone rhythm following suprachiasmatic lesions in the rat.

Reduced number of hypocretin neurons in human narcolepsy.

Suprachiasmatic nucleus : the mind's clock

A retinohypothalamic projection in the rat

Catecholamine innervation of the basal forebrain. IV. Topography of the dopamine projection to the basal forebrain and neostriatum.