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Rapid Spatial Reorientation and Head Direction Cells Michael B. Zugaro, Angelo Arleo, Alain Berthoz, and Sidney I. Wiener
 

Summary: Rapid Spatial Reorientation and Head Direction Cells
Michae¨l B. Zugaro, Angelo Arleo, Alain Berthoz, and Sidney I. Wiener
Centre National de la Recherche Scientifique­Colle`ge de France, Laboratoire de Physiologie de la Perception et de l'Action, 75231 Paris Cedex 05, France
Itissurprisinghowquicklywecanfindourbearingswhensuddenlyconfrontedwithafamiliarenvironment,forinstancewhenthelights
are turned on in a dark room. Subjectively, this appears to occur almost instantaneously, yet the neural processes permitting this rapid
reorientationareunknown.Alikelycandidateistheheaddirection(HD)cellsystem.Theselimbicneuronsfoundinseveralbrainregions,
including the thalamus and the hippocampus, discharge selectively when the head of an animal is oriented in a particular ("preferred")
direction. This neuronal activity is independent of position and ongoing behavior and is thus likely to constitute a physiological basis for
the sense of direction. Remarkably, although the HD cell system has properties resembling those of a compass, it is independent of
geomagnetic fields. Rather, the preferred directions of the HD cells are strongly anchored to visual cues in the environment. Here, we
bring evidence for the first time that a fundamental component of the capacity to rapidly reorient in a familiar environment may be
brought about by updating of HD cell responses as rapidly as 80 msec after changes in the visual scene. Continuous attractor networks
havebeenusedsuccessfullytomodelHDcellensembledynamics.Thepresentresultssuggestthatafterlargerotationsofthesurrounding
landmarks, activity in such networks may be propagated in abrupt jumps rather than in a gradually progressive manner.
Key words: anterodorsal thalamic nucleus; update latency; spatial memory; landmark; visual orientation; attractor network
Introduction
Head direction (HD) cells discharge selectively when the head of
a monkey, rat, mouse, or chinchilla is oriented in a particular
direction of the environment, which is referred to as the preferred
direction (Ranck, 1984; Knierim et al., 1998; Taube, 1998; Blair et

  

Source: Arleo, Angelo - Laboratory of Neurobiology of Adaptive Processes, Université Pierre-et-Marie-Curie, Paris 6

 

Collections: Biology and Medicine