Two types of hippocampal rhythmical slow activity in both the rabbit and the rat: Relations to behavior and effects of atropine, diethyl ether, urethane, and pentobarbital

摘要: Abstract A series of experiments in rats and rabbits indicates that the hip;ocampus receives two nonspecific inputs from brain stem, each capable producing rhythmical slow activity (theta rhythm). One type theta rhythm can be abolished by injections atropine sulfate (5 mg/kg, iv, or 25–50 ip) but not methyl nitrate. Such typically has a frequency 4 7 Hz occurs during ether urethane anesthesia as well behavioral immobility undrugged state. second is relatively unaffected large doses selectively induced anesthesia. 7–12 waking animals if, only such motor patterns head movements, walking, rearing are being performed concurrently. Both types elicited electrical stimulation at sites hypothalamus midbrain reticular formation. Atropine-sensitive may result excitation ascending cholinergic fibers, nature atropine-resistant system remains unknown. Atropine-resistant activation cerebrum play role emission control normal behavior mediate many effects centrally acting drugs anesthetics, tranquilizers, stimulants.