J Neurosci published a paper on hippocampal beta rhythm studied by array electrode

[Makoto Taketani]

Hi All,
I forgot to mention that we will be happy to send the reprint to people who
ask for it, when the reprint is available in mid December.

Thank you.
-makoto



-----Original Message-----
From: owner-mea-users at its.caltech.edu
[mailto:owner-mea-users at its.caltech.edu]On Behalf Of Makoto Taketani
Sent: Saturday, November 11, 2000 11:09 PM
To: mea-users at cco.caltech.edu; Connectionists at cs.cmu.edu;
cneuro at bbb.caltech.edu
Subject: MEA: J Neurosci published a paper on hippocampal beta rhythm
studied by array electrode


The following recent paper may be of interest to those in this list
interested in new methods to study in-vitro network operations.

The Journal of Neuroscience, November 15, 2000, 20(22):8462-8473
Origins and Distribution of Cholinergically Induced  Beta Rhythms in
Hippocampal Slices.
Ken Shimono1, Fernando Brucher2, Richard Granger2, Gary Lynch3, and Makoto
Taketani1

Regional variations and substrates of high-frequency rhythmic activity
      induced by cholinergic stimulation were studied in hippocampal slices
with
      64-electrode recording arrays. (1) Carbachol triggered beta waves
(17.6
      +/- 5.7 Hz) in pyramidal regions of 75% of the slices. (2) The waves
had
      phase shifts across the cell body layers and were substantially larger
in
      the apical dendrites than in cell body layers or basal dendrites. (3)
      Continuous, two-dimensional current source density analyses indicated
      apical sinks associated with basal sources, lasting approximately 10
msec,
      followed by apical sources and basal sinks, lasting approximately 20
msec,
      in a repeating pattern with a period in the range of 15-25 Hz. (4)
      Carbachol-induced beta waves in the hippocampus were accompanied by 40
Hz
      (gamma) oscillations in deep layers of the entorhinal cortex. (5)
      Cholinergically elicited beta and gamma rhythms were eliminated by
      antagonists of either AMPA or GABA receptors. Benzodiazepines markedly
      enhanced beta activity and sometimes introduced a distinct gamma
frequency
      peak. (6) Twenty Hertz activity after orthodromic activation of field
CA3
      was distributed in the same manner as carbachol-induced beta waves and
was
      generated by a current source in the apical dendrites of CA3. This
source
      was eliminated by high concentrations of GABA(A) receptor blockers. It
is
      concluded that cholinergically driven beta rhythms arise independently
in
      hippocampal subfields from oscillatory circuits involving (1) bursts
of
      pyramidal cell discharges, (2) activation of a subset of feedback
      interneurons that project apically, and (3) production of a
      GABA(A)-mediated hyperpolarization in the outer portions of the apical
      dendrites of pyramidal neurons.

SFN members can download the full article from
http://www.jneurosci.org/cgi/content/abstract/20/22/8462

The movie showing current source density of beta rhythms can be downloaded
from
http://www.med64.com/publications.htm

-------------------------------------------------------
Makoto Taketani, Ph.D.
Technology Development Center
Matsushita Electric Corporation of America
Irvine, CA
Net: taketani at med64.com
http://www.med64.com
-------------------------------------------------------



From: esann <esann at dice.ucl.ac.be>
To: "Connectionists at cs.cmu.edu" <Connectionists at cs.cmu.edu>
References: