Professor Pankaj Sah
Pankaj Sah, B.Sc., MBBS, Ph.D. is
Head of Synaptic Plasticity, Queensland Brain Institute at The
University of Queensland, Australia.
He was born in India and moved to Ethiopia for three years before
migrating to Australia with his family. He spent two years in San
Francisco, USA in his first postdoctoral position.
One project in his group is involved with examining the properties of
cells in the input side of the amygdala. He has shown that cells within
the lateral and basal nuclei can be divided into two broad categories:
pyramidal cells and interneurones. Pyramidal cells form the major type
of cell (93%) and are similar to excitatory cells found throughout the
cortex. The remaining cells (7%) are interneurones which are inhibitory
and form extensive connections with the excitatory cells in the
amygdala.
Surprisingly Pankaj found that the properties of
synaptic inputs
onto interneurones were quite different from those onto pyramidal cells.
These findings indicate that the modulation of inhibitory pathways may
be an important control mechanism within the amygdala. He is now
examining the properties of these neurons using a combination of
electrophysiological and imaging techniques.
Another project of his is studying the output side of the amygdala
—
the
central nucleus. This structure is divided into two main parts, the
medial and lateral. It has recently been shown that cells in the lateral
division are inhibitory and make local circuits while cells in the
medial division project out of the amygdala.
He has been
examining the
effects of a class of drugs called benzodiazepines (eg diazepam or
valium). These drugs are widely used as anxiolytics and their role in
the amygdala is of great interest. These drugs are thought to work by
potentiating the actions of the major inhibitory transmitter in the
brain, gamma amino butyric acid (GABA). He has found that the central
nucleus also contains a second type of GABA receptor which is inhibited
by benzodiazepines. This finding may have therapeutic implications as a
potential target for new classes of drugs.
Pankaj authored
Ca2+-activated K+ currents in neurones: types,
physiological
roles
and
modulation
and coauthored
Channels underlying neuronal calcium-activated potassium
currents,
Apical Dendritic Location of Slow Afterhyperpolarization Current in
Hippocampal Pyramidal Neurons: Implications for the Integration of
Long-Term Potentiation,
Physiological Role of Calcium-Activated Potassium Currents in the Rat
Lateral Amygdala,
Photolytic Manipulation of [Ca2+]i Reveals Slow
Kinetics
of
Potassium
Channels Underlying the Afterhyperpolarization in Hipppocampal Pyramidal
Neurons, and
Excitatory Synaptic Inputs to Pyramidal Neurons of the Lateral
Amygdala.
Pankaj earned his Ph.D. from the John Curtin School of Medical
Research for studies of ion channels in neurons in the limbic
system.
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