332 Book Reviews

from the latero-dorsal nuclei innervating the thalamus, the magnocellular cholinergic neurons in the basal fore- brain innervating the cortex.

The amygdala thus represents a nodal structure for sensory information processing, as Haigren speculates 'a metaphor for the connection of mind and body'.

Future research may determine the way in which sensory information is gated into the phylogenetic pro- gression from reptiles to man, and how, during normal circumstances, the amygdala may produce the emotional lift of enjoying life, the opposite sex, listening to music, and soon, and how the balance may be disturbed during extreme or pathological clinical conditions.

The substantial amounts of neurotransmitters/neuro- peptides within the amygdala undoubtedly contribute to adapt neuronal plasticity to new challenges.

The chapters on stimulus-reinforcement association present excellent discussions on the intimate functional interaction between the cortical regions of the temporal and orbital cortical regions (Rolls, Gaffan). I noticed in particular the possible role of the back-projections from the amygdala to the temporal neocortex as a guidance of stimuli representation and long-term storage of biological (novel) significant reinforcing stimuli (positive or nega- tive), their role for later recall and the significance of the orbital frontal cortex for rapid switching or reversals of changing reinforcement conditions. The rhinal cortex in the ventromedial temporal lobe is frequently lesioned in primate experiments intended for the amygdala or hippo- campal structures, but this cortical region is now con- sidered to contribute critically to recognition memory (Murray). In the rat amygdala, the encoding and memory formation seems particularly striking under conditions of a sufficient intensity of reinforcement for eliciting emotional reactions, arousal and autonomic changes (Kesner, McGaugh).

Ono et al. presented the functional electrophysiology on the temporal cortical-amygdala link to the lateral hypothalamus in the reward-output system. Everitt and Robbins contributed by discussing the role of the baso-

lateral amygdala and the mesolimbic dopamine system localized to the nucleus accumbens as the neural struc- tures involved in the expression of the motor elements of reward-related processes.

The final chapters (Aggleton, Gloor, Cain, Kling, Reynolds) present functional aspects of amygdala lesions or dysfunctions in humans in temporal lope epilepsy, kindling, schizophrenia, and the neuropathology of the amygdala in ageing and dementia (Mann).

I was surprised that this book did not contain a chapter on the current status of the amygdala and depression. However, this topic was certainly in focus in a recent book entitled The Mesolimbic Dopamine System: From Motivation to Action (eds P. Willner and J. ScheeI-Krfiger, 1991, J. Wiley & Sons), in which the mesolimbic dopa- mine system, and the role of the nucleus accumbens, were discussed to a large extent according to Mogenson's concept as the functional interphase for the mutual interaction between the major limbic structures, the hippocampus and the amygdala.

I think that this book should also have included a section on 'the extended amygdaloid complex' of Alheid and Heimer (1988) involving the basal forebrain.

This book is well written and contains only a few typographical errors. It was a pleasure to read it, and a substantial amount of new information has been accumu- lated since the last book published a decade ago. It now seems appropriate not only to consider the amygdala as a sensory gateway to emotions (Aggleton and Mishkin, 1986), but also to extend the status of this important struc- ture as a gateway for our understanding of the functions of the limbic system. The involvement of the amygdala in attention, emotion, motiviation, learning and memory becomes obvious.

Jgrgen Seheel-Kriiger Department of Psychopharmacology

NeuroSearch A/S Smedeland 26

DK2600 GIostrup Denmark

Functional Anatomy of the Neuroendocrine Hypothalamus

Edited by D. J. Chadwick and J. Marsh Published by John Wiley and Sons, Chichester, as volume 168 of the C I B A Founda t ion Symposium series ( ISBN 0 471 93440 2)

This book contains the proceedings of a meeting held in Budapest in October 1991 under the same title, and consists of 16 contributions of an international panel of experts on the subject.

In addition to the standard of the contributions, the scientific value of the book is certainly boosted by the reports of the discussions that followed each of the presen- tations. These discussion reports comprise approximately one third of the total volume of this publication and contain explicit references to published work. Often, they contain refreshing views that can be expected from an audience consisting of experts, all having their own history of scientific successes and fustrations.

The book is focussed on fundamental aspects of hypo- thalamic functioning rather than on clinical implications, as stated by S. L. Lightman in his introduction. Accord- ingly, most of the experimental findings presented here are derived from studies with experimental animals or cells.

Although the format of this series puts limitations on the number of contributors and thereby on the number of topics covered, I feel that the book gives a interesting overview of the state of the art in this particular field.

In this publication, the 'neuroendocrine hypothalamus 'refers primarily to those cells, nuclei and neuronal net- works that are responsible for the production, storage and secretion of hypophysiotropic signals and thereby to those cells that are directly involved in the control of specific functions of the pituitary gland. A recurrent theme is that the generation of physiologically relevant hypophysiotropic signals requires coordination of the se- cretory activity of a given set of neurons. Synchronization of secretory activity may be an intrinsic property of intercellular communication between a given group of peptidergic neurons. In support of this, the majority of the synapses found in the paraventricular and supraoptic nuclei were reported to be intrinsic, i.e. originate from

cells within these nuclei (M. Palkovits). The view that such intercellular contacts are crucial for pulsatile or rhythmic secretion of hypophysiotropic factors is supported by the results of transplantation studies (H. M. Charlton) and by studies demonstrating that immortalized GnRH neurons have the capacity to form networks and to secrete prod- ucts in a pulsatile manner (P, L. Mellon et al.). Although it remains to be demonstrated whether or not GnRH neurons in situ operate according to the same principles, evidence is presented indicating that suppression of gonadotropin secretion during the prepubertal phase in primates is due to a disturbance of synchronized firing of GnRH neurons rather than to their overall GnRH se- cretion (A. D. Perera and T. M. Plant). In addition, it is argued that the preovulatory surge of GnRH in mature animals requires a synchronized response to an array of extrinsic stimulatory and inhibitory neurotransmitter signals (C. A. Barraclough).

Oxytocin-prod ucing cells are known to show coordinated secretion and are described to exhibit soma-somatic con- tacts (juxtapositions). The occurrence of these contacts markedly increases when the neurons are activated. Also at the level of the posterior lobe, activity-associated morphological changes are found with an increase of neurosecretory terminals and a decrease of glial processes occupying the perivascular space (D. T. Theodosis and D. A. Poulain).

The control of growth hormone secretion requires co- ordinated secretion of stimulatory (GHRH) and inhi- bitory (somatostatin) signals in the portal blood. In his presentation, J. Epelbaum demonstrates that GHRH and somatostatin neurons form reciprocal contacts and express the proper receptors necessary to communicate with their physiological counterpart.

Evidence is steadily growing demonstrating that many neurosecretory neurons in the hypothalamus are multi- messenger neurons, i.e. express more than one neuropep- tide gent, and store and secrete more than one neuronally active substance (P. E. Sawchenko et al.). Examples are discussed demonstrating that coexpression can vary depending on hormonal, pharmacological or environ- mental manipulations (S. W. Young lII). This can be looked upon as a specific form of neuronal plasticity

Book Reviews 333

leading to changing bouquets of signalling substances. Another form of plasticity is presented by G. B. Makara, who demonstrated that after surgical ablation of the para- ventricular nucleus, other neurons can take over the role of the lesioned CRH neurons in mediating stress-induced ACTH secretion. Examples are presented demonstrating that the expression of specific neuropeptide genes can be affected by hormones, including effects of thyroid hor- mones on the expression of the TRH gene (R. M. Lechan and I. Kakucska). Such changes are often reversible and of relatively short duration. However, in some instances such changes persist long after the hormonal signal has ceased. Such plastic changes in gene transcription are described as "gene memory' by D. W. Pfaff et al. Speculations about the underlying mechanisms include methylation of a peptide gene and long-term effects on transcription factors. In addition to peptide genes, neuropeptide receptors can also be affected by (gonadal) hormones as discussed for oxytocin receptors by J. J. Dreifuss et al.

Following the pioneering work of J. C. Porter, tech- niques have become available to collect blood from the veins of the pituitary stalk for the determination of releas- ing and inhibiting factors. The techniques used in such studies with small rodents involve approaches (general anaesthesia, extensive surgery) that are not compatible with many physiological questions. In his contribution, 1. J. Clark describes chronic portal vein canulation in sheep that allows sampling of portal blood in freely moving unanaesthetized animals, and several lessons learned with this technique on the control of anterior pituitary hormone secretion.

Taken together, this book is an intersting conglomerate of papers and discussions on 16 topics, each of which may serve or have served as a symposium topic by itself. This makes the publication of interest for anatomists, neuroendocrinologists and physiologists working on, or interested in the function of the hypothalamus.

F. J. H, Tilders Department of Pharmacology

Free University 1081 BT Amsterdam

The Netherlands

Processing and Inhibition of Nociceptive Information (Proceedings of the International Symposium of the Osaka University for the Celebration of the 50th Anniversay)

R. Inoki , Y. Shigenaga and M. T o h y a m a (eds). Elsevier Science Publishers , The Nether lands , 1992.274 pages. ISBN 0-444-89501-9.

Processing and Inhibition q f Nociceptive Information is a timely and interesting contribution to the literature. The book contains contributions from a symposium organ- ized to celebrate the 50th anniversay of The University of Osaka. The breadth of material covered is wide-ranging, from studies employing molecular biological strategies to those describing recordings from human thalamus.

Although focusing on nociceptive processing and inhi- bition, this book is very different from proceedings of other recent pain-related symposia in that a significant proportion of the contributions deal with more clinically rclevant visceral and deep pain. The first three chapters address the processing of visceral nociception. Kumazawa and coworkers consider signal processing in canine testicu- lar polymodal nociceptors, Sugiura and coworkers address

differences between patterns of spinal termination of vis- ceral and somatic afferent fibers, and Kawatani and co- workers describe nociceptive afferent pathways innervating the urogenital tract.

Other contributions consider responses in the CNS fol- lowing experimental tissue injuries. For example, changes in the localization and the content of spinal cord neuro- peptides, gene expression for opioid peptides and immedi- ate early genes, and receptors in spinal cord following hind paw inflammation in the rat, capsaicin treatment of neonatal rats, and other manipulations constitute a sig- nificant proportion of the contributions. A number of these contributions utilize immunocytochemical localiza- tion of the protein product of the c-los proto-oncogene, for which Basbaum and Levine provide appropriate