title: Unilateral blockade of the dorsal ascending noradrenergic bundle and septal elicitation of hippocampal theta rhythm.
abstract: Unilateral blockade of the dorsal ascending noradrenergic bundle was produced by injections of procaine or of 6-hydroxydopamine. The threshold current of septal stimulation required to drive the hippocampal theta rhythm was then investigated at frequencies between 5.9 and 10.0 Hz. With both types of blockade the threshold-frequency function showed a normal 7.7 Hz minimum ipsilaterally and an abolition of the minimum contralaterally. Ventral noradrenergic bundle lesions had no effect. Septal elicitation of hippocampal theta rhythm may, therefore, be dependent on a noradrenergic mechanism controlling aspects of the theta rhythm, e.g. interhemispheric balance, which would not be obvious in ordinary spontaneous records.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D007839:Functional Laterality; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D006892:Hydroxydopamines / Q000494:pharmacology; D007031:Hypothalamus / Q000502:physiology; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000502:physiology*; D016627:Oxidopamine; D011343:Procaine / Q000494:pharmacology; D051381:Rats; D013826:Theta Rhythm
chemical_list: D006892:Hydroxydopamines; D011343:Procaine; D016627:Oxidopamine; D009638:Norepinephrine