Hypothermic rats at rectal temperatures below 30° C showed decreased duration of bar pressing for intracranial self-stimulation in lateral hypothalamic sites. The same effect was found in hungry rats. Both with cooling and hunger, decreased durations were accompanied by decreased thresholds. The threshold changes in hypothermic rats exceeded 12 μA in some cases. The results are relevant to explanations of why animals turn off rewarding brain stimulation. Particular attention is given to the possibility that cooling enhances neural activity in facilitatory connections between positive and aversive systems.
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References
1.
AnandB. K.PillaiR. V. (1967). Activity of single neurones in the hypothalamic feeding centres: effect of gastric distention. Journal of Physiology (London192, 63–77.
2.
BowerG. H.MillerN. E. (1958). Rewarding and punishing effects from stimulating the same place in the rat's brain. Journal of Comparative and Physiological Psychology51, 669–74.
3.
BrieseE.EcheverríaY.de QuijadaM. G. (1966). Ambient temperature and selfstimulation. Acta Physiologica Latino-Americana16, 209–15.
4.
FerrariE.AmanteaL. (1955). Convulsive electrocortical discharge in hypothermic dog. Electroencephalography and Clinical Neurophysiology7, 441.
5.
HamiltonC. L. (1967). Food and temperature. Handbook of Phsiology, Section 6Washington D.C.: American Physiological Society Vol. 1, 303–17.
6.
HerbergL. J.BlundellJ. E. (1969). Epileptiform seizures and the rat's choice of stimulus duration in electrical self-stimulation. Journal of Comparative and Physiological Psychology67, 442–7.
7.
HoebelB. G.TeitelbaumP. (1962). Hypothalamic control of feeding and selfstimulation. Science (New York135, 375–7.
8.
HoebelB. G.ThompsonR. D. (1969). Aversion to lateral hypothalamic stimulation caused by intragastric feeding or obesity. Journal of Comparative and Physiological Psychology68, 537–43.
9.
KeeneJ. J.CaseyK. L. (1970). Excitatory connection from lateral hypothalamic self-stimulation sites to escape sites in medullary reticular formation. Experimental Neurology28, 155–66.
10.
KoizumiK.BrooksC. McC.UshiyamaJ. (1959). Hypothermian and reaction patterns of the nervous system. Annals of the New York Academy of Sciences80, 449–56.
MrosovskyN. (1966). Self-stimulation in hypothermic hibernators. Cryobiology2, 229–39.
13.
MrosovskyN. (1967). Lowered body temperature, learning and behaviour. Mammalian Hibernation III.FisherK. C.DaweA. R.LymanC. P.SchönbaumE.SouthF. E.152–74.
14.
NoellK.BrillerS. A.BrendelW. B. (1952). Effects of cold exposure on brain activity. Federation Proceedings (Federation of American Societies for Experimental Biology11, 114.
15.
OomuraY.OoyamaH.YamamotoT.NakaF. (1967). Reciprocal relationship of the lateral and ventromedial hypothalamus in the regulation of food intake. Physiology and Behavior2, 97–115.
16.
PanuskaJ. A. (1969). The persistence and acute loss of previously learned behavior during progressive hypothermia. Depressed MetabolismMusacchiaX.SaundersJ. F.New York: American Elsevier Publishing Company375–426.
17.
PopovicP.SilverA. B.PopovicV. P. (1968). Critical temperature for intracranial self-stimulation in white rats. American Journal of Physiology214, 801–3.
18.
SchiffB. B.RusakB.BlockR. (1971). The termination of reinforcing intracranial stimulation: an ecological approach. Physiology and Behaviour7, 215–20.
19.
SpectorN. H.HamiltonC. L. (1967). Effects of ambient and internal temperatures upon intracranial self-stimulation. Virginia Journal of Science (Proceedings of the Virginia Academy of Science18, 201–2.
20.
SteinL. (1962). An analysis of stimulus-duration preference in self-stimulation of the brain. Journal of Comparative and Physiological Psychology55, 405–14.
21.
ValensteinE. S. (1964). Problems of measurement and interpretation with reinforcing brain stimulation. Psychological Review71, 415–37.
22.
ValensteinE. S.ValensteinT. (1963). When does reinforcing brain stimulation become punishing?. American Psychologist18, 436.
23.
ValensteinE. S.ValensteinT. (1964). Interaction of positive and negative reinforcing neural systems. Science (New York145, 1456–8.
