The activity-dependent strengthening and weakening of synaptic transmission are hypothesized to be the basis of not only memory and learning but also the refinement of neural circuits during development. Here we report that, in the developing CA1 area of the hippocampus, endocannabinoid (eCB)-mediated heterosynaptic long-term depression (LTD) of glutamatergic excitatory synaptic transmission is...

RGS2 is a member of the regulator of G-protein signaling (RGS) family and has been implicated in cellular mechanisms associated with neuronal plasticity. Long-term potentiation (LTP) of RGS2 knockout and wild-type mice was examined at the Schaffer collaterals to CA1 pathway in urethane-anesthetized mice in vivo to examine RGS2's possible role in the regulation of potentiation. As compared to wi...

The effect of metabotropic glutamate receptor (mGluR) activation on inhibitory synaptic transmission was examined by using whole cell patch-clamp recordings. Spontaneous (s) and miniature (m) inhibitory postsynaptic currents (IPSCs) were recorded from visually identified layer II/III pyramidal neurons in rat neocortex in vitro. Excitatory postsynaptic currents (EPSCs) were blocked by using bath...

The membrane current activated by fast nicotinic excitation of intact and mature rat sympathetic neurons was studied at 37 degrees C, by using the two-microelectrode voltage-clamp technique. The excitatory postsynaptic current (EPSC) was modeled as the difference between two exponentials. A fast time constant (tau2; mean value 0.57 ms), which proves to be virtually voltage-independent, governs ...

Growing evidence indicates that Wingless-type (Wnt) signaling plays an important role in the maturation of the central nervous system. We report here that Wingless-type family member 5A (Wnt-5a) is expressed early in development and stimulates dendrite spine morphogenesis, inducing de novo formation of spines and increasing the size of the preexisting ones in hippocampal neurons. Wnt-5a increas...

Spinal lamina II (substantia gelatinosa) neurons play an important role in processing of nociceptive information from primary afferent nerves. Anatomical studies suggest that neurons in the outer (lamina II(o)) and inner (lamina II(i)) zone of lamina II receive distinct afferent inputs. The functional significance of this preferential afferent termination in lamina II remains unclear. In this s...

Nucleus angularis (NA), one of the two cochlear nuclei in birds, is important for processing sound intensity for localization and most likely has role in sound recognition and other auditory tasks. Because the synaptic properties of auditory nerve inputs to the cochlear nuclei are fundamental to the transformation of auditory information, we studied the properties of these synapses onto NA neur...

Postsynaptic inhibition can operate by two distinct mechanisms: (1) membrane hyperpolarization and (2) shunting of excitatory postsynaptic currents. The arithmetic operations--either addition or multiplication--that synapses are able to perform during neuronal computations are determined by which of these two inhibitory mechanisms predominates. Hyperpolarizing IPSPs interact linearly with EPSPs...

Introduction: Previous studies indicate that exercise influences cognitive function. Nevertheless, considering that exercise in animal study can be voluntary, or forced, effects of exercise (specially forced exercise) on learning and memory abides as a matter of controversy. The present study aimed to investigate the effects of treadmill exercise on LTP in the dentate gyrus of rats. Methods: T...

More than 2.5 million Americans suffer a traumatic brain injury (TBI) each year. Even mild to moderate TBI causes long-lasting neurological effects. Despite its prevalence, no therapy currently exists to treat the underlying cause of cognitive impairment suffered by TBI patients. Following lateral fluid percussion injury (LFPI), the most widely used experimental model of TBI, we investigated al...