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Nardostachys jatamansi (Jones) DC. (Valerianaceae) is used in large quantities in the preparation of Ayurvedic and Unani drugs (1, 2). The decoction of the roots of this plant have been used for centuries in Ayurveda for epilepsy, hysteria, syncope, and mental weakness (3). Gupta et al. (4) reported that the ethanolic extract was found to be the most active and abolished the tonic extensor response in 50% of rats subjected to maximal electroshock seizures (MES). Jatamansone was found to be more effective than diphenylhydantoin (DPH) and the essential oil of N.jatamansi in MES. A preliminary study in our laboratory showed that the alcoholic extract of the roots of N. jatamansi increased the seizure threshold when tested against MES (25). Many investigations have been performed to determine the role of neurotransmitters in seizure mechanism. Several reports are available on the role of monoamine metabolism (5-8) and inhibitory amino acid metabolism (9, 10) in experimental as well as clinical seizures. But very few reports are available on the scientific evaluation of the effect of N.jatamansi extract on the activity of the brain. Hence, the present study was undertaken to evaluate the effect of the extract of N.jatamansi on biogenic amines and inhibitory amino acids in rat brain. Materials and Methods Animals Adult male albino Wistar rats weighing 180-250 g were used in the present study. The rats were housed in colony cages at an ambient temperature of 25 2°C and relative humidity of 50 10% with a light-dark cycle of 12 h each. They were fed standard pellet chow (purchased from Hindustan Lever, India) and water ad libif urn. In order to avoid the interference by the circadian rhythm in central nervous system amine content and turnover, all the experiments were performed at the same time of the day (8.00-11.00 am.). Drugs The roots of N.jafarnansi DC, (Valerianaceae) were purchased locally and identified by a pharmacognosist of the Department of Pharmacognosy, College of Pharmacy, Manipal where the voucher specimen has been deposited (No. 004083) aod were dried in shade, cleaned, and powdered to prepare the alcoholic extract. Extraction procedure and yield One kg of moderately powdered roots of N.jafamansi was extracted by refluxing with 95% alcohol in a Soxhlet extractor for 6-8 h. The extract was evaporated to dryness imder reduced pressure and temperature using flash evaporation and the dried residue was weighed and stored at 4°C. The yield of dry extract from the crude powder of N.jafarnansi was 8 %.

Young adult (60 day old) Wistar rats of either sex were orally intubated with 50 mg/kg body weight and 100 mg/kg body weight of aqueous root extract of Clitoria ternatea (CTR) for 30 days, along with age-matched saline controls. These rats were then subjected to passive avoidance tests and the results from these studies showed a significant increase in passive avoidance learning and retention. Subsequent to the passive avoidance tests, these rats were killed by decapitation. The amygdala was processed for Golgi staining and the stained neurons were traced using a camera lucida and analysed. The results showed a significant increase in dendritic intersections, branching points and dendritic processes arising from the soma of amygdaloid neurons in CTR treated rats especially in the 100 mg/kg group of rats, compared with age-matched saline controls. This improved dendritic arborization of amygdaloid neurons correlates with the increased passive avoidance learning and memory in the CTR treated rats as reported earlier. The results suggest that Clitoria ternatea aqueous root extract enhances memory by increasing the functional growth of neurons of the amygdala.