{"id":329,"date":"2008-06-01T00:00:00","date_gmt":"1970-01-01T00:00:00","guid":{"rendered":"http:\/\/wptest.psych.ualberta.ca\/~cdickson\/wordpress\/?p=329"},"modified":"2008-06-01T00:00:00","modified_gmt":"1970-01-01T00:00:00","slug":"median-raphe-stimulation-disrupts-hippocampal-theta-via-rapid-inhibition-and-state-dependent-phase-reset-of-theta-related-neural-circuitry","status":"publish","type":"post","link":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/median-raphe-stimulation-disrupts-hippocampal-theta-via-rapid-inhibition-and-state-dependent-phase-reset-of-theta-related-neural-circuitry\/","title":{"rendered":"Median raphe stimulation disrupts hippocampal theta via rapid inhibition and state-dependent phase reset of theta-related neural circuitry"},"content":{"rendered":"<p>PMID: <a href='http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/18436639' title=''>18436639<\/a><\/a><\/p>\n<p>Jackson J, Dickson CT, Bland BH<\/p>\n<p>J. Neurophysiol. 2008 Jun;99(6):3009-26<\/p>\n<h2>Abstract<\/h2>\n<p><p>Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization. However, few studies have evaluated theta-related neural circuitry during MR manipulation. In urethane-anesthetized rats, we investigated the effects of MR stimulation on hippocampal field and cell activity using high-frequency (100 Hz), theta burst (TBS), and slow-frequency electrical stimulation (0.5 Hz). We demonstrated that high-frequency stimulation of the MR did not elicit deactivated patterns in the forebrain, but rather elicited low-voltage activity in the neocortex and small-amplitude irregular activity (SIA) in the hippocampus. Both hippocampal phasic theta-on and -off cells were inhibited by high-frequency MR stimulation, although MR stimulation failed to affect cells that had neither state or phase relationships with theta field activity. TBS of the MR-induced theta field activity phase locked to the stimulation. Slow-frequency stimulation elicited a state-dependent reset of theta phase through a short-latency inhibition (5 ms) in phasic theta-on cells. Subpopulations of phasic theta-on cells responded in either oscillatory or nonoscillatory patterns to MR pulses, depending on their intraburst interval. off cells exhibited a state-dependent modulation of cell firing occurring preferentially during nontheta. The magnitude of MR-induced reset varied as a function of the phase of the theta oscillation when the pulse was administered. Therefore high-frequency stimulation of the MR appears to disrupt hippocampal theta through a state-dependent, short-latency inhibition of rhythmic cell populations in the hippocampus functioning to switch theta oscillations to an activated SIA field state.<\/p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>PMID: 18436639 Jackson J, Dickson CT, Bland BH J. Neurophysiol. 2008 Jun;99(6):3009-26 Abstract Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization. However, few studies have evaluated theta-related neural circuitry during MR manipulation. In urethane-anesthetized rats, we investigated the effects of MR stimulation on hippocampal field and cell activity using high-frequency [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-329","post","type-post","status-publish","format-standard","hentry","category-uncategorized","post-preview"],"_links":{"self":[{"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/posts\/329","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/comments?post=329"}],"version-history":[{"count":0,"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/posts\/329\/revisions"}],"wp:attachment":[{"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/media?parent=329"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/categories?post=329"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.psych.ualberta.ca\/brainrhythmslab\/wp-json\/wp\/v2\/tags?post=329"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}