Long-term potentiation (LTP) is a long-lasting enhancement of synaptic function induced by a brief high-frequency tetanus. Excitatory amino acids (EAA), particularly glutamate and aspartate are a topic of increasing research interest with regard to their proposed involvement in the pathogenesis of a variety of neurological and psychiatric disorders, some of which are associated with a loss of learning and memory abilities. LTP of excitatory synaptic transmission is a candidate for the neural mechanism underlying learning and memory. LTP has certian properties and characteristics that coincide with voltage-dependent properties of N-methyl-D aspartate (NMDA) receptor. In hippocampal CA1 area, there are at least two forms of LTP, one is NMDA receptor-dependent LTP, and the other is NMDA receptor-independent LTP. Excitatory pathways that utilize NMDA receptors are also involved in the initiation of seizures and their propagation. These NMDA-induced convulsions can be reversed by anticonvulsant drugs or NMDA antagonists. There are reports suggesting that a significant number of people with epilepsy have cognitive difficulties and impaired memory. Some epileptic patients show memory dysfunctions associated with chronic anticonvulsant therapy. Some anticonvulsant drugs which interfere with NMDA receptor system directly or indirectly, possibly influence the expression of LTP. Long-term depression (LTD) is also being considered as a candidate mechanism for memory formation in hippocampus. LTP and LTD also share a few common features. Some areas which remain to be explored include:- Will LTP and the NMDA receptor turn out to be the true molecular foundations of human memory? To what extent the link between LTP and NMDA systems mediate epilepsy ?

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The paper traces the genesis of Pharmacology in India, to the early pioneers. It reflects on several facets and trends in the growth of Pharmacology during the current century under several subheads: Pharmacology and clinical care; Pharmacology as a career; Nonmedical personnel in Pharmacology; Undergraduate teaching of Pharmacology; Pharmacology, Pharmacy and Pharmaceutical companies; Postgraduate training in Pharmacology; Research; Clinical Pharmacology; Animal experiments. It concludes reflecting on the glowing role of Pharmacology in this century and its promise for the coming millenium.

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Objective: To compare the proconvulsive potential of some currently available fluoroquinolones namely ciprofloxacin, ofloxacin and pefloxacin on electro convulsion and chemoconvulsion in rats and mice respectively and to correlate the same with the clinical reports. Methods: The animals were treated intraperitoneally with 12.5 and 25mg/kg, of ciprofloxacin, ofloxacin or pefloxacin and then subjected to maximal electroshock seizures (MES), subconvulsive doses of pentylenetetrazole(PTZ) and theophylline (40 and 125mg/kg. i.p. respectively). Results: Ciprofloxacin and pefloxacin employed in the higher dose had significant worsening effect on MES. Tonic extensor phase was prolonged from 11.6 ( 0.4 secs in control group to 38.11( 5.38 secs and 23.5 ( 4.5 secs with higher doses of ciprofloxacin and pefloxacin respectively, while both the doses of ofloxacin had no statistically significant effect on this parameter. On administration of subconvulsive dose of PTZ, both the doses of ofloxacin and higher doses of ciprofloxacin and pefloxacin showed significant worsening effect. Lastly, on coadministration with theophylline both the doses of ofloxacin and higher dose of pefloxacin had significant proconvulsant effect. Ciprofloxacin in both the doses did not show any significant proconvulsant effect. Conclusion: The results indicate that all the three fluoroquinolones especially ofloxacin should be used with caution in patients with predisposing epileptogenic factors. Also the model of chemoconvulsions showed better clinical correlation for proconvulsive property of fluoroquinolones.

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Objective: To synthesize and study the hypotensive and (-blocking activity of some new 6-(alkylamino hydroxy propoxy) benzothiadiazines. Methods: The hypotensive activity was studied in normotensive albino rats at a single dose of drug (1 mg/kg body wt.) and compared wiht that of same dose of propranolol. The (-blocking effect was assessed as the percentage blockade of the effect of adrenaline (5(g) by the drugs (50(g) on Frog's isolated heart. Results: Administration of the synthesized drugs showed significant reduction in blood pressure comparable to that of propranolol at 1 mg/kg body weight dose level. Some of the derivatives (50(g) completely blocked the adrenaline (5(g) induced chronotropic effect on frog's isolated heart. Conclusion: Our experiment suggests that the compounds synthesized have significant (-blocking and hypotensive activity and may be recommended for further investigation.

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Objective: To study the vascular responses in streptozotocin-induced diabetic monkeys. Methods: The monkeys were anaesthetized and a section of thoracic aorta was removed and cut into transverse strips. Vessels were suspended in a 10 ml organ bath containing Hank's physiological solution oxygenated with 100% oxygen. The tissues were equilibrated for 90 minutes under a resting tension of 3 g. Isometric tensions were recorded with a force displacement transducer and recorded on a student physiograph. After equilibration period, the relaxant and contractile responses were observed in control and diabetic monkey aortic strips. Results: The percent relaxation to acetylcholine was decreased in diabetic monkey aortic strips, whereas the percent relaxant response to sodium nitroprusside did not differ significantly. This indicates impaired endothelium dependent relaxation in diabetic monkey aortic strips. In addition, the contractility to phenylephrine was increased in monkey aortic strips but not to potassium chloride. There was structural and functional impairment observed in diabetic monkey aortic tissues. Conclusion: The monkey aortic strips from streptozotocin-induced diabetic monkeys showed structural and functional impairment.

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