scholarly journals On the influence of exercise on the weight of the central nervous system of the albino rat

1911 ◽  
Vol 21 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Henry H. Donaldson
1956 ◽  
Vol 185 (3) ◽  
pp. 601-606 ◽  
Author(s):  
Alan G. Slocombe ◽  
Hudson Hoagland ◽  
Lillian S. Tozian

Lysergic acid diethylamide (LSD), 5-hydroxytryptamine, and adrenochrome were shown to have properties similar to epinephrine in their effects on the spontaneous electrical activity in the brain of the albino rat. The effects of these drugs were shown to be determined by the type of anesthetic used. In Pentothal-anesthetized animals, profound reduction of the electrical activity in both frequency and amplitude was found in response to these drugs, while in ether-anesthetized animals there was no significant effect. There was a tendency for LSD to increase electrical activity when injected following recovery from anesthesia. The significance of this differential response is discussed with respect to structures in the central nervous system primarily affected by ether and Pentothal, and it is suggested that the site of action of these compounds is in Pentothal-sensitive nonspecific pathways. The site of the depressive action of these drugs with Pentothal is further defined by the fact that both cortical and subcortical structures were equally affected, while respiratory and cardio-regulatory centers were not significantly depressed. This implicates one of the lower nonspecific centers with widespread cortical and subcortical projections.


1951 ◽  
Vol 7 (3) ◽  
pp. 271-279 ◽  
Author(s):  
J. T. EAYRS

The growth of the body and central nervous system and the emergence of stereotyped behaviour have been studied in male and female rats during the first 24 days of life. The effects of daily injections of equine gonadotrophin on these measures have also been investigated. The weight of the body and of the central nervous system was significantly less in the female than in the male. The daily administration of 10 i.u. of equine gonadotrophin was without effect on either. The movements of the trunk and limbs concerned in the body-righting reflex became coordinated more slowly in the gonadotrophin-injected animals than in their litter-mate controls. At 15 days old, male rats were able to right in mid-air more successfully than litter-mate females. The placing reflex appeared earlier in the male than in the female. Its appearance was accelerated in the females given gonadotrophin, but not in the males. In the ventral funiculus of the spinal cord of 24-day-old experimental animals, the axis cylinders occupied more space relative to that occupied by myelin than did those of the controls. The total amount of myelin present was unchanged. There was no sex difference in the progress of myelination in the spinal cord. The significance of these findings in relation to the secretion of sex hormones is discussed. It is suggested that the secretion of androgen may be responsible for an acceleration of nervous maturation.


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