The synthesis of Fos, the protein product of the immediate early gene c- fos, was used to map metabolically some of the neural substrates of conditioned fear in the rat. Analysis of the behaviors emitted by the rats during the test session provided strong evidence that the conditioning procedure was effective. Exposure to the environment in which they had previously received footshock significantly increased the number of Fos-like immunoreactive neurons in nearly 50 brain regions, both cortical and subcortical. Among the structures showing the most dramatic increases in fear-induced c-fos expression were the cingulate, piriform, infralimbic, and retrosplenial cortices, the anterior olfactory nucleus, claustrum, endopiriform nucleus, nucleus accumbens shell, lateral septal nucleus, various amygdalar nuclei, paraventricular thalamic nucleus, ventral lateral geniculate nucleus, the ventromedial, lateral, and dorsal hypothalamic nuclei, the ventral tegmental area, and the supramammillary area. These data demonstrate that a relatively simple classical conditioning procedure activates a large number of widely dispersed cortical and subcortical structures. Some of the structures showing increased c-fos expression have important autonomic functions and may therefore have reflected centrally mediated changes in blood pressure and respiration produced by the anxiogenic stimuli. In a second experiment, the effects of pretreatment with the anxiolytic drug diazepam (2.5, 5.0, or 10 mg/kg) were evaluated. The benzodiazepine produced dose-related decreases in the frequency of crouching (freezing) elicited by the aversively conditioned contextual cues. Diazepam also produced dose-related decreases in conditioned stress-induced c-fos expression in all but one structure, the effects being statistically significant in 38 of 60 sampled structures. Diazepam dose dependently increased fear-induced c- fos expression in the central nucleus of the amygdala. There was considerable regional variability with respect to sensitivity to diazepam, the retrosplenial cortex and the supramammillary area being the only two structures to show decreases after the lowest dose of diazepam. In contrast, the entorhinal cortex, nucleus accumbens core, ventromedial and posterior hypothalamic nuclei, median raphe, and locus coeruleus were particularly resistant to diazepam, all failing to show statistically significant decreases in conditioned fear-induced c-fos expression even at the highest dose. The extent to which diazepam decreased conditioned stress-induced c-fos expression was unrelated to previous estimates of benzodiazepine receptor density in the sampled structures.

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A holistic account of the human brain is provided by the Second Law of Thermodynamics. According to this universal precept, the central nervous system is governed by the quest to consume free energy in the least possible time. The brain is like any other system of nature that has evolved over eons and continues to develop over an individual's life time. This physical portrayal is singularly appropriate because power-law characteristics as well as oscillatory and at times unpredictable functioning are not exclusive attributes of the brain but are found in other systems throughout nature. The neural network comprises pathways for signal propagation just as other natural systems have pathways for the transmission of energy in various forms. These universalities support the view of the evolution and development of the human brain as a natural thermodynamic process. In a like manner perception, sensation and learning as well as the processes of memory, emotions and consciousness can be regarded as natural expressions of the neural network under the suzerainty of the Second Law. The outcomes of cognitive processes, like other natural processes, are non-deterministic because the interactive effects of flows of energy as signals with differences in energy as their driving forces cannot be separated from each other. This naturalistic framework also provides insight into mental disorders and cognitive defects.

Bathing creates some of the highest levels of discomfort in the lives of individuals diagnosed with dementia. The present study measured the frequency of 14 agitated behaviors during bathing in 15 elderly residents with dementia residing in a continuing care center. Each resident was observed for four sessions of two different bathing methods, the conventional tub bath and a modification of the bed bath, known as the Thermal bath. The summed frequencies of all agitated behaviors was significantly less for the Thermal bath than the tub bath. This overall effect was greater in men than women and in one particular behavior, shivering. The results suggest that for individuals with dementia the Thermal bath offers a viable alternative to the conventional tub method. Further research may clarify other parameters, such as cost effectiveness and long-term effects of the use of non-rinse cleansers for elderly individuals.

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Rhesus monkeys showed normal postoperative reaction times. (RT) following unilateral section of the medullary pyramids. However, a slowness in RT of the forelimb contralateral to the lesion appeared in two-choice RT tasks in which no choice-resolving pretrial cues were present in the environment. Pyramidotomized monkeys had no difficulty in stopping a movement quickly and accurately at a specified point in space. The impaired forelimb exhibited a greater loss of strength in flexion than in extension. The weakness in flexion was greater at the wrist than at the elbow or shoulder. The percentage of pyramidal tract destroyed correlated significantly with the severity of the strength deficit. Amphetamine injections temporarily ameliorated the contact-placing reaction deficit of the pyramidal limb.Clinical neurology has assigned to the extensive postoperative training in recovpyramidal tract (PT) the role of mediat-ery from motor lesions has been stressed ing voluntary movement (Walshe, 1961, (Bucy, Ladpli, & Ehrlich, 1966 Liu & Chapter 1). Selective lesions of the PT in Chambers, 1962). Accordingly, one goal of monkeys (Lawrence & Kuypers, 1968) the present study in examining the defhave revealed that while independent icits following pyramidotomy was to emmovement of the digits is abolished, the ploy prolonged postoperative forced trainremaining limb joints recover a high de-ing. In a series of experiments, Evarts gree of proficiency. The limbs are, how- (1966, 1968, 1969) has described the ever, slow-moving and weak. These con-changes in firing rates and latencies of elusions derive from clinical observations PT cell neurons in the monkey precentral of operates with relatively little formal cortex in response to displacement, speed, postoperative training. The importance of and force of wrist movement. The second "^TluTresearch was supported by a Postdoctoral g°a l °f, this stud {. Was t0 P r °vide a COI °-Fellowship (NB 30, 021-12 NSRB) from the Na-plimentary quantitative analysis of the

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