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Faculty
 Srdjan
D. Antic
Assistant Professor of Neuroscience
antic@neuron.uchc.edu
Research Interests:
- Prefrontal and somatosensory cortex;
- Pyramidal neurons;
- Synaptic transmission
- Excitatory neurotransmitters;
- The role of dendrites in synaptic integration;
- Dopaminergic modulation of dendritic excitability
Project Description:
Project Description: Dopamine is synthesized in neurons whose cell
bodies are located in the brain stem. One group of dopamine-producing
neurons (ventral tegmental area) sends their long axons to the
prefrontal cortex (Figure 1). Electron microscope studies in monkey and
human clearly demonstrate that dopamine synaptic contacts onto cortical
neurons are located almost exclusively on the distal dendrites and
spines of distal dendrites (Figure 2). What is the functional
significance of glutamate-dopamine ultrastructural juxtaposition? Why is
it necessary to have a dopamine release site right next to the glutamate
release site, on the same dendritic spine? Is dopamine involved in the
precise control of the excitatory glutamatergic synapse?
The level of prefrontal cortex dopamine is critical for modulating
normal cognitive/behavioral processes. One important hypothesis is that
deviations from the critical levels can severely disrupt cognitive
processes and result in mental disorders such as schizophrenia. At
present, it is not known how dopamine interacts with prefrontal cortex
neural circuits.
We are using in vitro experimental methods to study how dopamine
affects glutamate-evoked dendritic membrane potentials. Distal dendritic
regions of thin dendrites, where the interaction between glutamatergic
and dopaminergic signals actually takes place, are difficult to probe
with glass electrodes. In order to measure directly the dendritic
response to glutamatergic excitation we use optical recording
techniques. Optical methods adopted in our laboratory are based on
intracellularly applied calcium-sensitive and voltage-sensitive dyes
(Figure 3).
Figure 3. Dendritic imaging. Simultaneous whole-cell (channel 0) and
fast multi-site voltage-sensitive dye recordings from the dendritic tree
(channels 1-17). A doublet of action potentials was evoked by direct
current injection in the soma (modified from Antic, 2003).
Selected Publications:
Antic SD, Acker CD, Zhou WL, Moore AR and Milojkovic BA (2008) The
role of dendrites in the maintenance of UP state. In: Mechanisms of
spontaneous active states in neocortex. Ed. Timofeev I. Research
Signpost, Kerala India.
Zhou WL, Yan P, Wuskell JP, Loew LM, Antic SD (2008) Dynamics of
action potential backpropagation in basal dendrites of prefrontal
cortical pyramidal neurons. European Journal of Neuroscience.
(4):923-36.
Milojkovic BA, Zhou WL, Antic SD (2007) Voltage and calcium
transients in basal dendrites of the rat prefrontal cortex. Journal of
Physiology. 585(Pt 2):447-68.
Milojkovic B, Radojicic M, and Antic SD (2005) A strict correlation
between dendritic and somatic plateau depolarizations in the rat
prefrontal cortex pyramidal neurons. Journal of Neuroscience
25(15):3940-51.
Milojkovic BA, Wuskell JP, Loew L, and Antic SD (2005) Initiation of
sodium spikelets in basal dendrites of neocortical pyramidal neurons.
Journal of Membrane Biology 209(2): 155-169.
Milojkovic B, Radojicic M, Goldman-Rakic P, and Antic SD (2004) Burst
generation in rat pyramidal neurones by regenerative potentials elicited
in a restricted part of the basilar dendritic tree. Journal of
Physiology 558(1): 193-211.
Antic SD, (2003) Action potentials in basal and oblique dendrites of rat
neocortical pyramidal neurons. Journal of Physiology (550(1): 35 - 50.
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