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Fallahnezhad, M.

Publications and source records attributed to Fallahnezhad, M..

2 recordsLinked to original sources

The cerebellum promotes sequential foraging strategies and contributes to the directional modulation of hippocampal place cells

The cerebellum contributes to goal-directed navigation abilities and place coding in the hippocampus. Here we investigated its contribution to foraging strategies. We recorded hippocampal neurons in mice with impaired PKC-dependent cerebellar functions (L7-PKCI) and in their littermate controls while they performed a task where they were rewarded for visiting a subset of hidden locations. We found that L7-PKCI and control mice developed different foraging strategies: while control mice repeated spatial sequences to maximize their rewards, L7-PKCI mice persisted to use a random foraging strategy. Sequential foraging was associated with more place cells exhibiting theta-phase precession and theta rate modulation. Recording in the dark showed that PKC-dependent cerebellar functions controlled how self-motion cues contribute to the selectivity of place cells for both position and direction. Thus, the cerebellum contributes to the development of optimal sequential paths during foraging, possibly by controlling how self-motion and theta signals contribute to place cells coding. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/526971v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@1a4e344org.highwire.dtl.DTLVardef@449ab8org.highwire.dtl.DTLVardef@9aa45org.highwire.dtl.DTLVardef@89c110_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Cerebellar Control of a Unitary Head Direction Sense

Head direction (HD) cells, key neuronal elements in the mammalians navigation system, are hypothesized to act as a continuous attractor network, in which temporal coordination between cell members is maintained under different brain states or external sensory conditions, resembling a unitary neural representation of direction. Whether and how multiple identified HD signals in anatomically separate HD cell structures are part of a single and unique attractor network is currently unknown. By manipulating the cerebellum, we identified pairs of thalamic and retrosplenial HD cells that lose their temporal coordination in the absence of external sensory drive, while the neuronal coordination within each of these brain regions remained intact. Further, we show that distinct cerebellar mechanisms are involved in the stability of direction representation depending on external sensory conditions. These results put forward a new role for the cerebellum in mediating stable and coordinated HD neuronal activity toward a unitary thalamocortical representation of direction.

neuroscience↗