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The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

39 goldfish, either normal, sham operated, or forebrain ablated, were tested in the acquisition, extinction, and retention of an instrumental avoidance response with either a short or long delay between operations and testing. Forebrain removal severely impaired or prevented acquisition, greatly reduced resistance to extinction, and completely abolished a previously learned response. The deficits were permanent-an 8-wk. delay between operations and testing did not result in improved performances. Median escape latencies did not differ between groups, indicating that the deficit is specific to avoidance learning.

STRICKER, E. M., AVD HAINSWORTH, F. R. 1970. Evaporative cooling in the rat: Effects of dehydration.Can. J. Physiol. Plaarmacol. 48,[18][19][20][21][22][23][24][25][26][27] Previous investigations dcmonstrrited that the water loss of rats associated with increased sajivary evaporation during heat stress is derived from both intracellular and intravascular sources. The present studies indicate that sufficient delaydration of either fluid compartment will impair temperature regulation. Salivary excretion from all dehydrated rats was virtually abolished at ambient temperatures below 38-40 "C, but temperature regulation was still possible if a large temperature gradient existed between the animals and the environment. Above these ambient temperatures, where increased evaporation is essential to survival, the rate of evaporative water loss returned to normal. However, body water reservoirs in dehydrated rats were rapidly depleted, salivary evaporation could not be maintained, and survival times were shortened. In contrast, access to drinking water significantly increased thermal tolerance. These results emphasize the importance of adequate body fluid hydration for evaporative cooling through saliva spreading by rats in the heat. In addition, they indicate that allocation of body water for evaporation takes precedence over conflicting demands for water conscrvation during heat stress.

Rats cool themselves in the heat by evaporating saliva groomed onto their body surfaces. Previous reports indicated that surgical removal of the submaxillary glands severely impaired evaporative water loss and body temperature regulation, whereas parotid desalivation had little effect. In the present experiments saliva was collected directly from the oral cavities of rats exposed to heat stress and was identified by its sodium concentration to determine the roles of individual salivary glands as thermoregulatory effectors. The fundamental difference between the glands was that submaxillary secretion was initiated at a lower level of hyperthermia (38.5 °C) than parotid secretion (40.0 °C), and thus made a greater contribution to thermoregulation. For example, normal rats secreted only submaxillary saliva at an ambient temperature of 36 °C and secreted three times more submaxillary saliva than parotid saliva at 40 °C. These results indicate that the submaxillary glands are primary thermoregulatory effectors of rats during heat stress, and that the parotid glands provide supplementary secretion only during pronounced hyperthermia.