Shivering in the Rat Produced by Electrical Self Stimulation of the Septum

During the course of the development of a reliable technique and test for implanting self-stimulating electrodes in the rat brain we observed that electrical self stimulation of the lateral septal nucleus consistently produced shivering. To the best of our knowledge this reaction following septal self stimulation has not been reported before and confirms the recent report of Stuart, Kawamura, and Hemingway ( 1961) of this effect following electrical stimulation of the ventrolateral region of the septum in cats. METHOD Male hooded rats, approximately 450 gm. in weight, were used. Three animals had electrodes impIanted successfully in the lateral septal nucleus and gave reliable results; and three animals with electrodes implanted in the caudate nucleus, ventral nucleus of the thalamus, and corpus callosurn served as controls. The electrodes were .009-in. stainless steel wire insulated with Formvar enamel except at the tip. Two such electrodes were cemented together and formed a bipolar assembly. Electrodes were placed in the appropriate neural structures by means of a calibrated stereotaxic instrument, and fixed permanently to the skull by means of stainless steel screws and dental cement. The self-stimulation equipment was a Scientific Prototype lever box. The sides were increased to 18 in. to prevent the animal from escaping, and the lever was increased in length by 2 in. to make the bar more accessible. The stimulus was a stepped down 60-cycle alternating current delivered through a pair of flexible hearing aid leads, suspended over the open box by a strip of chin rubber, which were actached to the animal's head by small insulated alligator clips. Stimulus duration was held constant at 0.5 sec. and was independent of the length of time the lever was depressed. It was impossible co deliver a second stimulus during the duration of the first. A bypass switch enabled E to stimulate at any time. Animals were allowed to recover for one week following surgery. Each animal was tesced for 30 min. on each of three successive days in the lever box. Animals with electrodes in the septum learned to depress the lever and stimulate themselves very rapidly. Intensity of stimulacion was adjusted to produce an optimum response rate during the first test period. In the control animals stimu'Thls research was supported by Grant B-776 from rhe National Institute of Neurological D~seases and Blindness, United Srates Public Health Service. -51SF Undergraduate Summer Fellow

Anesthesia · Electrical brain stimulation · Shivering · Stimulation · Medicine · Neural dynamics and brain function · Neuroscience · Neuroscience and Neural Engineering · Photoreceptor and optogenetics research · Psychology