On reversible deafness, generalized anxiety disorder, and the motoric brain: a psychophysiological perspective.

Electromyographic (EMG) recording during presentation of loud sounds revealed central motor inhibition in a rare case of conversion disorder with deafness. Two subjects in whom hypnotic deafness was induced resembled the patient. In contrast, patients with generalized anxiety disorder (GAD) showed a significantly delayed return of EMG to baseline, compared with normals and schizophrenics following administration of auditory startle stimuli.

On electromyographic (EMG) gradients and movement-related brain activity: significance for motor control, cognitive functions, and certain psychopathologies.

Electromyographic (EMG) voltage that rises continuously during motor performance or mental activity and falls precipitately at the end is known as an EMG gradient. Our review is based on 55 studies of EMG gradients, which were published during the period 1937-1994. The extremely wide diversity of situations yielding EMG gradients suggests the possibility that these gradients may be universal accompaniments of organized goal-directed behavioral sequences, overt and covert.

Effects of intracerebroventricular angiotensin II and olfactory stimuli on multiple unit activity in preoptic and anterior hypothalamic areas: medial-lateral comparison.

Under urethane anesthesia multiple unit activity (MUA) recordings were taken from medial and lateral preoptic and anterior hypothalamic sites in 21 rats during multiple dose intracerebroventricular (i.vt.) injections of angiotensin II (AII), using artificial CSF as control.

Individual consistency and modifiability of lapping rates in rats: a new look at the variance--invariance question.

Lapping rates were recorded from water-deprived rats over 3-week periods when they were young adults and again, 9.4 months later, when they were middle-aged. Test-retest correlation coefficients of 0.

Cardiovascular and respiratory responses to electrical stimulation of the midbrain in the rat.

In descending through the midbrains of rats with stimulation electrodes, we have observed some remarkable reversals of pressor and depressor autonomic effects as the electrode was moved from one locus to another. Autonomic effects of stimulating in the midbrain areas that we studied are of special interest because stimulations in some of these midbrain loci have pain-relieving effects (Hosobuchi et al., 1977, 1979; Mayer et al.

Experiments on the neuropsychology of thirst.

We report the results of a series of experiments whose main objectives are: (a) the identification of neural receptors for thirst; and (b) other neural structures of critical importance for thirst and drinking behavior. We have used results from hypertonic challenges during acute unit and multiple-unit recording experiments to identify responsive brain areas for behavioral study in chronic experiments. Results include the following.

Multiple unit activity recorded longitudinally in rats from pubescence to old age.

Longitudinal multiple unit activity (MUA) recordings of excellent quality over time periods as long as 26 months are described. The validity of the method was demonstrated by showing persistence of specific and idiosyncratic MUA responses to controlled sensory stimulation over these long time periods. This longitudinal MUA method was used to study level of localization neuronal activity as a function of aging.

On movement-related forebrain and midbrain multiple unit activity in rats. II. Some constraints on movement.

In 18 rats multiple unit activity was recorded simultaneously from ventral forebrain, dorsal midbrain, and other areas, with continuous monitoring by sensitive head movement and body movement recorders, along with careful observations or ongoing behaviors. In the preceding article of this series, we reported significant covariations between neural activity and motoric activity in forebrain and midbrain areas in the rat. In the present article, we pointed out exceptions to this general finding.

Responses of lateral preoptic neurons and behavioral reactions to angiotensin II and hypertonic NaCl and sucrose administered into the rat cerebral ventricle.

In 18 acutely prepared rats and in 3 chronically implanted rats, multiple-unit responses of lateral preoptic area (LPOA) neurons to angiotensin II (A II) and hypertonic NaCl and sucrose injected into the lateral ventricle were recorded. In addition, behavioral reactions were observed in the chronically prepared rats. Results showed that i.

Responses of lateral preoptic neurons in the rat to hypertonic sucrose and NaCl.

Multiple-unit recordings were taken from the lateral preoptic region during a series of hypertonic and isotonic NaCl and sucrose intracarotid injections. Subjects were 11 hooded rats (8 males and 3 ovariectomized females) under urethane anesthesia. The data showed that under favorable cannulation conditions there were strong multiple-unit responses to hypertonic sucrose injections, and that under these conditions NaCl injections were not significantly more effective than sucrose injections.

Movement-related forebrain and midbrain multiple unit activity in rats.

In 16 rats multiple unit activity was recorded simultaneously from ventral forebrain and dorsal midbrain areas, with continuous monitoring by sensitive head movement and body movement recorders, along with careful observations of ongoing behaviors. Both forebrain and midbrain multiple unit activity were significantly correlated with head and body movements: recordings from both brain areas showed significant declines corresponding to decline in recordings head and body movement. The declines in midbrain multiple unit activity were significantly greater than those in forebrain multiple unit activity.

Osmosensitive neurons in the rat's dorsal midbrain.

In experiment 1, multiple unit recordings were taken simultaneously from lateral preoptic and dorsal midbrain areas during a series of intracarotid hypertonic and isotonic NaCl injections. Subjects were 15 hooded rats (11 males and 4 ovariectomized females) under urethane anesthesia. Results showed that the neuronal reactions to a series of hypertonic NaCl injections (0.

Rod and cone sensitivity in destriate monkeys.

Photopic and scotopic spectral sensitivity of rhesus monkeys was determined before and after complete removal of the striate cortex. The monkeys were required to choose between a white and a series of monochromatic stimuli distributed throughout the visible spectrum. A modified method of limits was used to determine the psychophysical point of subjective equality at which the colored and white lights were perceived as being equally bright.

Osmosensitive neurons in the rat's preoptic area: medial-lateral comparison.

For the first time, brain-recording data were brought to bear directly on the question of a critical osmosensitive zone in the lateral preoptic area as specifically delimited in the rat by Blass and Epstein, and in the rabbit by Peck and Novin. Our data clearly showed that this critical zone in the lateral preoptic area of the rat contains cells that are osmosensitive. Simultaneous recording from cell populations (a) inside the critical zone and (b) in a zone medial to it showed that the net acceleratory response to challenge for the former was much greater than it was for the latter.

Slowing of heart rate after septal self-stimulation in rats.

Heart rate, recorded continuously from rats trained to press a bar for intracranial electrical stimulation of their septal areas, fell consistently after brain stimulation. Interpretation of the rewarding effect of septal stimulation had previously been limited by the absence of any data on the autonomic effects of the stimulation. The results of this study suggest that the rewarding effect may possibly be produced by a parasympathetic (quieting) reaction of the autonomic nervous system to septal stimulation.