BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:CA1 OLM cells generate and modulate hippocampal theta oscillations
  
DTSTART:20120227T100000
DTEND:20120227T110000
DTSTAMP:20260509T054311Z
UID:4990d1aaecc138186b55138cc5be578f5c471834ea6ab59acb718eb9
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Richardson N Leao\nAssistant Professor\, Department of N
 euroscience\, Uppsala University\, Uppsala\, Sweden\nAssociate Professor\,
  Brain Institute\, Federal University of Rio Grande do Norte (UFRN)\, Braz
 il\nAbstract : Theta oscillations are regular and pronounced brain rhythms
  (4-12 Hz) involved in a multitude of cognitive processes\, but the mechan
 isms behind their generation are still subject to intense debate. For deca
 des\, theta rhythmogenesis has been attributed to extra-hippocampal struct
 ures\, especially to the medial septum/diagonal band of Brocca (MS/DBB) co
 mplex. In this work we show that theta oscillations can be generated in vi
 vo by increasing the excitability of one single type of hippocampal intern
 euron\, the oriens lacunosum-moleculare cells (OLM cells). In addition\, o
 ptogenetic inhibition of OLM cells significantly decreases theta amplitude
  in animals anesthetised with urethane or performing exploratory behaviour
 . Our experiments further show that OLM cells can entrain the activity of 
 pyramidal cell assemblies. We hypothesize that theta pacemaking activity i
 n OLM neurons is produced by a combination of three factors\, 1) intrinsic
  membrane properties\, 2) the connectivity to pyramidal cells\, and 3) the
  presence of gap junctions between OLM cells. Our results show a clear cor
 relation between the activation of a well-defined interneuron population a
 nd the production of a network phenomenon ubiquitous to all mammals\, i.e.
  theta oscillations. It furthermore demonstrates that the hippocampus is c
 apable of generating theta oscillations independently of other structures\
 , suggesting that an intrinsic hippocampal theta pacemaker could co-exist 
 with extra-hippocampal rhythm generators.
LOCATION:EPFL – SV 1717A http://plan.epfl.ch/?lang=fr&room=SV+1717A
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR