Learned helplessness: effects on brain monoamines and the pituitary-gonadal axis.

The effect of the learned helplessness paradigm, a model of depression, on biogenic amines in eight brain regions, and on the serum levels of luteinizing hormone, corticosterone, and testosterone in male rats was determined. Rats which were exposed to uncontrollable and unpredictable shocks (HY-rats) had hormone levels similar to those in appropriate control animals. However, HY-rats had higher levels of 5-HIAA in the pons/medulla oblongata and lower levels of 5-HT in the cortex than rats which could escape the shocks (HE-rats).

Activity wheel stress: changes in brain norepinephrine turnover and the occurrence of gastric lesions.

The effects of activity wheel stress on brain regional norepinephrine (NE) and 3-methoxy-4-hydroxyphenylglycol (MHPG) content and on the occurrence of gastric lesions were investigated. Multiple gastric lesions were present in the stomachs of all rats exposed to activity wheel stress (AW). No gastric lesions were observed in any of the food consumption (FC) or untreated (UC) control rats.

Activity-wheel stress: effects on brain monoamines and the pituitary-gonadal axis.

The study was designed to study the possible role of dopaminergic and serotonergic systems in pituitary gonadal function following activity stress. 3 groups of rats were caged individually. 1 group of rats (AW) was fed for 1 h each day and had free access to a running wheel.

Specific binding of the muscarinic antagonist [3H]quinuclidinyl benzilate is not associated with preganglionic motor neurons in the dorsal motor nucleus of the vagus.

The present study evaluates the binding of [3H]quinuclidinyl benzilate, [3H]QNB, as a measure of cholinergic muscarinic binding in six areas of the rat medulla oblongata associated with the cranial nerves. In an experimental group, the right vagus nerve was severed in the neck in order to determine whether the specific muscarinic binding sites might be located on cells that contribute efferent fibers to the vagus nerve. The level of activity of choline acetyltransferase (ChAT) also was determined in the same six areas.

Loss of Purkinje cell-associated benzodiazepine receptors spares a high affinity subpopulation: a study with pcd mutant mice.

In order to identify the relative number of benzodiazepine (BZ) receptors in Purkinje and granule cells, the Purkinje cell degeneration (pcd) mutant mouse was used at different ages. In these mice, Purkinje cells have degenerated almost completely by 45-50 days of age. Granule cell loss occurs only later, and is most severe between 180 and 300 days.

Catecholamines and serotonin in the caudal medulla of the rat: combined neurochemical-histofluorescence study.

The distribution of monoamine transmitters among the nuclei of the caudal medulla was determined through the combined use of the Falck-Hillarp histofluorescence method for cellular localization of catecholamines and serotonin and quantitative micropunch neurochemical assays of norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT) content using high performance liquid chromatography with electrochemical detection. These combined methods permit a direct correlation between neurotransmitter levels and fluorescent fiber and perikaryal profiles. Eight medullary nuclei were sampled: (1) dorsal motor nucleus of X and ventral nucleus solitarius, (2) the dorsomedial reticular formation, (3) the hypoglossal nucleus, (4) the ventromedial reticular formation, (5) the nucleus ambiguus, (6) nuclei raphe obscurus and pallidus, (7) the inferior olivary nucleus and (8) the descending (spinal) nucleus of V.

Distribution and uptake of glycine, glutamate and gamma-aminobutyric acid in the vagal nuclei and eight other regions of the rat medulla oblongata.

In order to study the central neurochemical control of the vagus nerve, the contents of glycine, GABA, glutamate and five other amino acids have been measured in ten anatomically distinct regions of the rat medulla oblongata. Additionally, the high affinity uptake of glycine, GABA, glutamate, and leucine were measured in the same ten medullary regions. The data support published evidence for glutamatergic and GABAergic transmission in the nucleus of the tractus solitarius (NTS), and glycinergic inhibition in the hypoglossal nucleus.

Religion and death: The clerical perspective.

This first descriptive report on the perspectives, experiences, and actions of clergy relative to terminal patients and their families details a highly emotionally charged complex of interactions. Some 276 clerics from fourteen different bodies provided information on their involvement in death-work, spiritual and personal resources, satisfactions and doubts, pastoral goals and purposes, and their background and outlooks regarding their own demise. Implications of these findings are explored with respect to various forms and contents of training and experience.

In vitro release of endogenous amino acids from granule cell-, stellate cell-, and climbing fiber-deficient cerebella.

The K+-stimulated, Ca2+-dependent release of glutamate, aspartate, gamma-aminobutyric acid (GABA), alanine, taurine, and glycine was measured in slices of cerebella obtained from control, and granule cell-, granule cell plus stellate cell-, or climbing fiber-deficient cerebella of the rat. The 55 mM-K+-stimulated release of glutamate and GABA was 10-fold greater in the presence of Ca2+ than in its absence. The stimulated release of aspartate was 4-fold higher when Ca2+ was present in the bathing media, while the value for alanine was twice as high as the amount obtained in the absence of Ca2+.

Regional distribution of cholinergic parameters within the rat striatum.

The topographical distribution of choline acetyltransferase, muscarinic receptor binding and high affinity choline uptake was studied in 21 separate areas of the rat striatum. The areas of the nucleus chosen represented dorsolateral, dorsomedial, ventrolateral and ventromedial regions along the rostrocaudal aspect of the striatum, such that a three-dimensional distribution of the cholinergic parameters could be obtained. Within any given rostrocaudal section, no significant dorsoventral differences were noted for any of the cholinergic parameters.

Levels of glutamate, aspartate, GABA, and taurine in different regions of the cerebellum after x-irradiation-induced neuronal loss.

The levels of glutamate (Glu), aspartate (Asp), gamma-amino-n-butyric acid (GABA), and taurine (Tau) were determined in the cortex, molecular layer, and deep nuclei of cerebella of adult rats exposed to X-irradiation at 12-15 days following birth (to prevent the acquisition of late-forming granule cells; 12-15x group) and 8-15 days following birth (to prevent the acquisition of granule and stellate cells; 8-15x group). Also, the levels of the four amino acids were measured in the crude synaptosomal fraction (P2) isolated from the whole cerebella of the control, 12-15x, and 8-15x groups. The level of Glu was significantly decreased by (1) 6-20% in the cerebellar cortex; (2) 15-20% in the molecular layer; and (3) 25-50% in the P2 fraction of the X-irradiated groups relative to control values.

Red - green opponent spectral sensitivity: disparity between cancellation and direct matching methods.

The spectral sensitivity at the opponent stage of the visual system is traditionally measured by a hue-cancellation procedure. Comparison with a direct hue-matching method shows that cancellation overestimates short-wavelength sensitivity by as much as a factor of 30. The observation implies that different mechanisms control the perception of short-wavelength and long-wavelength redness.