Cortical and thalamic connections of the representations of the teeth and tongue in somatosensory cortex of new world monkeys

Connections of representations of the teeth and tongue in primary somatosensory cortex (area 3b) and adjoining cortex were revealed in owl, squirrel, and marmoset monkeys with injections of fluorescent tracers. Injection sites were identified by microelectrode recordings from neurons responsive to touch on the teeth or tongue. Patterns of cortical label were related to myeloarchitecture in sections cut parallel to the surface of flattened cortex, and to coronal sections of the thalamus processed for cytochrome oxidase (CO). Cortical sections revealed a caudorostral series of myelin dense ovals (O1-O4) in area 3b that represent the periodontal receptors of the contralateral teeth, the contralateral tongue, the ipsilateral teeth, and the ipsilateral tongue. The ventroposterior medial subnucleus, VPM, and the ventroposterior medial parvicellular nucleus for taste, VPMpc, were identified in the thalamic sections. Injections placed in the O1 oval representing teeth labeled neurons in VPM, while injections in O2 representing the tongue labeled neurons in both VPMpc and VPM. These injections also labeled adjacent part of areas 3a and 1, and locations in the lateral sulcus and frontal lobe. Callosally, connections of the ovals were most dense with corresponding ovals. Injections in the area 1 representation of the tongue labeled neurons in VPMpc and VPM, and ipsilateral area 3b ovals, area 3a, opercular cortex, and cortex in the lateral sulcus. Contralaterally, labeled neurons were mostly in area 1. The results implicate portions of areas 3b, 3a, and 1 in the processing of tactile information from the teeth and tongue, and possibly taste information from the tongue.     

The role of Gateway drugs and psychosocial factors in substance dependence in Eastern India

OBJECTIVE: Western studies have identified the gateway patterns of substance use which lead the way from the so called "Soft Drugs" (like nicotine, etc.) to the "Hard Drugs" (like Opioids) [the Gateway hypothesis]. Nicotine and alcohol have been implicated as the most common initiating drugs in studies from different places, however, studies are lacking from this region. This study was designed to find the drugs of initiation and to understand the factors for initiation, maintenance, and relapse of these substances in persons dependent on them in Eastern India. METHOD: Seventy subjects with ICD 10 DCR diagnosis of substance dependence admitted consecutively in Center for Addiction Psychiatry, Central Institute of Psychiatry (CIP), Ranchi, were taken up for the study after taking written informed consent. A semistructured questionnaire including the substance use part of Mini International Neuropsychiatric Inventory (MINI) was administered. RESULTS: Alcohol and opioids were the most common drugs of dependence but nicotine and alcohol were found to be the most common initiating drugs in both alcohol and opioid groups. Persons dependent on opioids presented earlier for treatment, with earlier development of withdrawal symptoms and having completed lesser years of formal education, and had higher monthly incomes as compared to those dependent on alcohol. The most common psychosocial factors determining initiation and maintenance were peer pressure or curiosity. CONCLUSIONS: If adolescents and youth can be motivated to stay away even from the "gateway drugs" by targeting common initiation factors, it may lead to delay in dependence or possibly avoidance of development of dependence.     

Comparative efficacy and safety of oxcarbazepine versus divalproex sodium in the treatment of acute mania: A pilot study

ObjectiveThis study compared the efficacy and safety of oxcarbazepine and divalproex sodium in acute mania patients.Subjects and methodsIn this 12 week, randomized, double-blind pilot study, 60 patients diagnosed with acute mania (DSM-IV) and a baseline Young Mania Rating Scale (YMRS) score of 20 or more received flexibly dosed oxcarbazepine (1000–2400 mg/day) or divalproex (750–2000 mg/day). The mean decrease in the YMRS score from baseline was used as the main outcome measure of response to treatment. A priori protocol-defined threshold scores were ≤12 for remission and ≥15 for relapse. Number of patients showing adequate response and the time taken to achieve improvement was compared. Adverse events were systematically recorded throughout the study.ResultsOver 12 weeks, mean improvement in YMRS scores was comparable for both the groups including the mean total scores as well as percentage fall from baseline. There were no significant differences between treatments in the rates of symptomatic mania remission (90% in divalproex and 80% in oxcarbazepine group) and subsequent relapse. Median time taken to symptomatic remission was 56 days in divalproex group while it was 70 days in the oxcarbazepine group (p = 0.123). A significantly greater number of patients in divalproex group experienced one or more adverse drug events as compared to patients in the oxcarbazepine group (66.7% versus 30%, p < 0.01).ConclusionOxcarbazepine demonstrated comparable efficacy to divalproex sodium in the management of acute mania. Also the overall adverse event profile was found to be superior for oxcarbazepine.     

Antiepileptic potential of flavonoids fraction from the leaves of Anisomeles malabarica

Ethnopharmacological relevance

The plant Chodara (Anisomeles malabarica R.Br. Family: Lamiaceae) has numerous therapeutic utilities in folk medicine.

Aim of the study

To isolate and evaluate the anti-epileptic potential of fractions from the ethyl acetate extract (EAE) of Anisomeles malabarica leaves.

Materials and methods

The EA extract (2.12% w/w) of the leaves of Anisomeles malabarica was prepared and fractionated into total flavonoids fraction (AMFF) and tannins fraction (AMTF), which subsequently evaluated for the antiepileptic activity against PTZ- and MES model in wistar rats. Diazepam and phenytoin (2 mg/kg and 25 mg/kg, i.p., respectively), were used as a reference drugs. Further, the presence of flavonoid was confirmed by chemical test, TLC and HPTLC were done for the identification of the number of flavonoids with reference to standard.

Results

Single dose pretreatment with AMFF (25 and 50 mg/kg, i.p.) has found to be effective against both MES and PTZ-convulsions, but associated with a marked decrease in locomotor activity and motor activity performance (i.e., neurotoxic effects), similar to that of diazepam treatment. Interestingly, chronic treatment with AMFF at lower doses (6.25 and 12.5 mg/kg, i.p., 1 week) has also produced significant antiepileptic activity, but without causing neurotoxic effects.

Conclusion

Thus, it may be concluded that the flavonoids fraction of the EA extract of Anisomeles malabarica leaves has antiepileptic potential against both MES and PTZ convulsion models. Acute treatment (25 and 50 mg/kg, i.p.) is associated with neurotoxic activity. Whereas, chronic treatment (6.25 and 12.5 mg/kg, i.p., 1 week) also shown significant antiepileptic effect without causing neurotoxic side effects. However, further research is in progress to determine the component(s) of the flavonoids fraction of Anisomeles malabarica involved and their mechanism of action in bringing about the desirable anti-epileptic effect.