Rat

Effects of diet and type of nesting material on the reproduction and lactation of the rat

Reproductive improvements due to paper nesting material were dramatic. The 10.8 pups per litter weaned by mothers nested in paper was very significantly higher than the 7.0 pups weaned by those with wood shaving. A more sensitive measure of the...

Year Published: 1966Animal Type: Rat, Rodent

Citation: Nolen, G. A., Alexander, J. C. 1966. Effects of diet and type of nesting material on the reproduction and lactation of the rat. Laboratory Animal Care [Laboratory Animal Science] 16, 327-336.

Adrenocortical response to novelty and noxious stimulation

It was found in rats that the magnitude of the stress response to being transferred into an experimental cage is virtually the same as that produced by electrical shock. ... Exposure to a new environment, or novelty, may contribute significantly...

Year Published: 1967Animal Type: Rat, Rodent

Citation: Friedman, S. B., Ader, R. 1967. Adrenocortical response to novelty and noxious stimulation. Neuroendocrinology 2, 209-212.

Comparison of behavioural development in socially isolated and grouped rats

Single-housed males showed reduced activity and a greater incidence of stereotypical tail manipulation [substitute social response?] and pawing with hind legs than males housed in groups.

Year Published: 1967Animal Type: Rat, Rodent

Citation: Baenninger, L. P. 1967. Comparison of behavioural development in socially isolated and grouped rats. Animal Behaviour 15, 312-323.

Social and nonsocial attraction in rats

Single rats show a reduction of fear in a strange environment when another - though anesthetized - rat is present.

Year Published: 1968Animal Type: Rat, Rodent

Citation: Latane, B., Glass, D. 1968. Social and nonsocial attraction in rats. Journal of Personality and Social Psychology 9, 142-146.

Gregariousness and fear in laboratory rats

In a novel open-field environment rats showed less signs of fear [number of fecal boluses excreted] when tested in pairs versus alone. The presence of a caged companion was less effective than a free-moving companion in reducing fear.

Year Published: 1969Animal Type: Rat, Rodent

Citation: Latane, B. 1969. Gregariousness and fear in laboratory rats. Journal of Experimental Social Psychology 5, 61-69.

Rat brain: Effects of environmental enrichment on wet and dry weights

Wet weight of rat cerebral cortex was increased by exposure to an enriched environment [10 or 12 animals in large cage with toys], as compared with standard colony [2 or 3 animals in small cage] or impoverished conditions [single-housing].

Year Published: 1969Animal Type: Rat, Rodent

Citation: Bennett, E. L., Rosenzweig, M. R., Diamond, M. C. 1969. Rat brain: Effects of environmental enrichment on wet and dry weights. Science 163, 825-826.

Elevation of adrenal Tyrosine hydroxylase and phenylethanolamine-N-methyl transferase by repeated immobilization of rats

Immobilization result in a neuronally dependent elevation of tyrosine hydroxilase in the adrenal medulla.

Year Published: 1970Animal Type: Rat, Rodent

Citation: Kvetnansky, R., Weise, V. K., Kopin, I. 1970. Elevation of adrenal Tyrosine hydroxylase and phenylethanolamine-N-methyl transferase by repeated immobilization of rats. Endocrinology 87, 744-749.

Adrenal and urinary catecholamines in rats during adaption to repeated immobilization stress

Rats subjected to daily immobilization for up to one year still excreted greater amounts of epinephrine than did control animals or animals after their first immobilization. These increases levels of urinary ephinephrine were not accompanied by a decrease in adrenal...

Year Published: 1970Animal Type: Rat, Rodent

Citation: Kvetnansky, R., Mikulaj, L. 1970. Adrenal and urinary catecholamines in rats during adaption to repeated immobilization stress. Endocrinology 87, 738-743.

Studies of brain weight and RNA content after short periods of exposure to environmental complexity

Rats in Environmental Complexity (EC) were compared with litter mates maintained in Impoverished Conditions (IC) for various times. An initial relatively fast onset of the difference between the cerebral weight of the EC and IC rats was observed. This phase...

Year Published: 1970Animal Type: Rat, Rodent

Citation: Ferchmin, P. E., Eterovic, V. A., Caputto, R. 1970. Studies of brain weight and RNA content after short periods of exposure to environmental complexity. Brain Research 20, 49-57.

Rats’ preference for earned in comparison with free food

When work demands are not too high, rats prefer earned food to free food.

Year Published: 1970Animal Type: Rat, Rodent

Citation: Carder, B., Berkowitz, K. 1970. Rats' preference for earned in comparison with free food. Science 167, 1273-1274.