Biology Reference
In-Depth Information
3.
C
ONCLUSION
In this chapter, we focused on the roles of ECs as retrograde modulators of short-term
and long-term forms of synaptic plasticity. It is now widely accepted that ECs are released
from postsynaptic neurons in an activity-dependent manner and induce transient or persistent
suppression of transmitter release. These EC- mediated forms of synaptic plasticity are
observed in various brain regions including the striatum, hippocampus, cortex, neocortex,
amygdale, NAc, and cerebellum. Because CB1 is widely distributed in the CNS, it is expected
that the EC signaling may be involved in synaptic plasticity throughout the CNS and
contribute to various aspects of brain functions. In addition to the roles as retrograde
messengers at synapses, ECs have other important functions that are discussed elsewhere. For
example, ECs are reported to control the excitability of neocortical GABAergic interneurons
in an autocrine manner [11]. ECs also play an important role in neuroprotection [196]. As
reviewed in this chapter, recent studies have greatly expanded our knowledge of the EC
system in the CNS. The development in EC research is also very important from a clinical
point of view, because the EC system has been expected to provide potential targets not only
for the treatment of habit forming behaviors but also neurological disorders.
4.
A
CKNOWLEDGEMENTS
The authors acknowledge support in part by grants from the National Institutes of Health
(NIH AA11031 and NS049442), and the New York State Psychiatric Institute (BSB).
5.
R
EFERENCES
[1]
Abood, M.E., Ditto, K.E., Noel, M.A., Showalter, V.M., Tao, Q. (1997). Isolation and
expression of a mouse CB1 cannabinoid receptor gene. Comparison of binding
properties with those of native CB1 receptors in mouse brain and N18TG2
neuroblastoma cells.
Biochem Pharmacol
, 53, 207-214.
[2]
Alger, B.E. (2002). Retrograde signaling in the regulation of synaptic transmission:
focus on endocannabinoids.
Progress in Neurobiology
, 68, 247-286.
[3]
Alger, B.E., Pitler, T.A., Wagner, J.J., Martin, L.A, .Morishita, W., Kirov, S.A., Lenz,
R.A. (1996). Retrograde signalling in depolarization-induced suppression of inhibition
in rat hippocampal CA1 cells.
J Physiol
, 496, 197-209.
[4]
Anwyl, R. (1999). Metabotropic glutamate receptors: electrophysiological properties
and role in plasticity.
Brain Res Brain Res Rev
, 29, 83-120.
[5]
Arancio, O., Kandel, E.R., Hawkins, R.D. (1995). Activity-dependent long-term
enhancement of transmitter release by presynaptic 3',5'-cyclic GMP in cultured
hippocampal neurons.
Nature
, 376, 74-80.
[6]
Arancio, O., Kiebler, M., Lee, C.J., Lev-Ram, V., Tsien, R.Y., Kandel, E.R., Hawkins,
R.D. (1996). Nitric oxide acts directly in the presynaptic neuron to produce long-term
potentiation in cultured hippocampal neurons.
Cell
, 87, 1025-1035.
