2009年10月26日

Place cells know their place

As we move around, spatial information is encoded and processed by 'place' cells in the hippocampus.

Each of these neurons increases its firing rate when situated in its 'place', thus equating rate coding with location.

The firing patterns of hippocampal place cells have been studied extensively over the past 40 years and theoretical models have been proposed to explain the mechanisms responsible for encoding place and time in newral circuits.

Now the development of techniques allowing intracellular recording from place cells in awake, behaving mice navigating a virtual reality maze makes it possible to test these models.

Initial results point to the existence of two subthreshold signatures of place fields : an incrase in the amplitude of membrane potential oscillations at theta frequencies and a ramp - like depolarization of baseline membrane potential.


### DataBace ###
nature Vol.461 439-558 Issue no.7263 24 September 2009
Article p.941 / Intracellular dynamics of hippocampal place cells during virtual navigation / C D Harvey et al. (Princeton University)
News and Views p.889 / Neuro Science : The insaide story on place cells / Douglas Nitz


Hippocanpal place cells encode spatial information in rate and temporal codes.

To examine the mechanisms underlying hippocampal coding, here we measured the intracellular dybamics of place cells by combining in vivo whole-cell recordings with a Virtual-reality system.

Haed-restrained mice, running on a spherical treadmill, interacted with a computer-generated visual environment to perform spatial behaviours.

Robust place-cell activity was present during movement along a virtual linear track.

From whole-cell recordings, we identified three subthreshold signatures of place fields : an asymmetric ramp-like depolarization of the baseline membrane potential, an increase in the amplitude of intracellular theta oscillations, and a phase precession of the intracellular theta oscillation relative to the extracellularly recorded theta rhythm.

These intracellular dynamics underline the primary features of place-cell rate and temporal codes.

The virtual-reality system developed here will enable new experimental approaches to study the neural circuits underlying navigation.


【関連する記事】
posted by 0≠素子 at 18:39| Comment(0) | brain | このブログの読者になる | 更新情報をチェックする
この記事へのコメント
コメントを書く
お名前:

メールアドレス:

ホームページアドレス:

コメント:

認証コード: [必須入力]


※画像の中の文字を半角で入力してください。
×

この広告は1年以上新しい記事の投稿がないブログに表示されております。