Long-term potentiation

Limited clinical data on BMY 21502 (11) suggest that some benefit may be provided to patients with dementia (87,88). This expectation is based on the abihty of (11) to increase the level of arousal and attention in patients with certain types of dementia. BMY 21502 enhances long-term potentiation... 

AVP is excitatory in the ventral hippocampus, either directly or by potentiation of glutamatergic responses. An inhibitory effect has been observed in AVP may be involved in the formation of long-term potentiation and thus learning and memory. However, AVP is proconvulsive, may augment the formation of dmg tolerance and dependence, and affects cardiovascular regulatory processes. 

Each alternative should be assessed in terms of the extent to which it mitigates short- and long-term potential exposure to any residual contamination and protects human health, both during and after implementation of the corrective measure. 

Long-term potentiation (LTP) is a synaptic plasticity phenomenon that corresponds to an increase in the synaptic strength (increase in the post-synaptic response observed for the same stimulation of the presynaptic terminals) observed after a high frequency stimulation (tetanus) of the afferent fibres. This increased response is still observed hours and even days after the tetanus. The phenomenon is often observed at glutamatergic synapses and involves, in most cases, the activation of the V-methyl D-aspartate (NMDA) subtype of ionotropic glutamate receptors. 

Functions of nNOS include long-term regulation of synaptic transmission in the CNS (long-term potentiation, long-term depression), whereas there is no evidence for an involvement of nNOS-derived NO in acute neurotransmission. Retrograde communication across synaptic junctions is presumed to be involved in memory... 

Locus Cemleus Long-Chain Fatty Acids Long-QT Syndromes Long-Term Depression Long-Term Potentiation Loop Diuretics... 

Li ST, Matsushita M, Moiiwaki A, Saheki Y, Lu YF, Tomizawa K, Wu HY, Terada H, Matsui H (2004) HIV-1 Tat inhibits long-term potentiation and attenuates spatial learning [corrected]. Ann Neurol 55(3) 362-371... 

Despite the above precautions, it is still possible that NT spillover and extrasynaptic action may occur and indeed could be required in some instances. Thus the diffusion of glutamate beyond the synapse could activate extrasynaptic high-affinity NMDA or metabotropic receptors (Chapter 9) to produce long-lasting effects to maintain activity in a network. This may be important in long-term potentiation and memory effects. Crosstalk between synapses could also act as a back-up to ensure that a pathway functions properly (see Barbour and Hausser 1997). 

Williams, JH and Bliss, TV (1989) An in vitro study of the effect of lipoxygenase and cyclooxygenase inhibitors of arachidonic acid on the induction and maintenance of long-term potentiation in the hippocampus. Neurosci. Lett. 107 301-309. 

Stella N, Schweitzer P, Piomelli D. A second endogenous cannabinoid that modulates long-term potentiation. Nature 1997 388 773-778. 

Collins DR, Pertwee RG, Davies SN. Prevention by the cannabinoid antagonist, SR141716A, of cannabinoid-mediated blockade of long-term potentiation in the rat hippocampal slice. Br J Pharmacol 1995 115 869-870. 

Long-term potentiation and depression of glutamatergic synapses are involved in many models for brain function and development. A key factor in the plasticity is a change in the AMPA and kainate... 

Stanton, P. K. Sarvey, J. M. (1987). Norepinephrine regulates long-term potentiation of both the population spike and dendritic EPSP in hippocampal dentate gyrus. Brain Res. Bull. 18, 11519. 

Lanahan A et al. Selective alteration of long-term potentiation-induced transcriptional response in hippocampus of aged, memory-impaired rats. J Neurosci 1997 17 2875-2885. 

Haul S, Schrader J, Haas HL, Luh-mann HJ. Impairment of neocortical long-term potentiation in mice deficient of endothelial nitric oxide synthase. J Neurophysiol 1999 81 494—497. 

Weisskopf M, Zalutsky R, Nicoll RA. The opioid peptide dynorphin mediates heterosynaptic depression of hippocampal mossy fibre synapses and modulates long-term potentiation. Nature 1993 365 188-190. 

The NMDA receptor is an ionotropic glutamate receptor involved in fast excitatory neurotransmission. It plays a key role in a variety of CNS functions, most notably long-term potentiation (LTP) and neuronal plasticity, and is regulated by several mechanisms. One such mechanism involves the amino acid glycine (1). 

---