Arachidonic acid released from striatal neurons by joint stimulation of ionotropic and metabotropic quisqualate receptors.

Associative stimulation of N-methyl-D-aspartate (NMDA) receptors and quisqualate ionotropic receptors (Qi) induces long-term potentiation at particular glutamatergic synapses. Release of arachidonic acid as a result of stimulation of NMDA receptors has been proposed to play a part in the establishment of long-term potentiation. But long-term plasticity events at some other glutamatergic synapses do not involve activation of NMDA receptors. Here we report that in mature striatal neurons in primary cultures, quisqualate can release arachidonic acid by associatively activating both quisqualate metabotropic receptors coupled to phospholipase C (Qp) and Qi receptors. Independent activation of these two receptor types with specific agonists did not stimulate arachidonic acid release. These results support a role for the associative activation of Qp and Qi receptors in synaptic plasticity events, including long-term potentiation at particular synapses.

[A case of sepsis caused by Edwardsiella tarda complicated panophthalmitis and pyogenic spondylitis].

Edwardsiella tarda (E. tarda) is gram negative enterobacteriaceae which has been found generally in animal hosts and occasionally in human feces. We have reported a case of sepsis caused by E. tarda, complicated panophthalmitis and pyogenic spondylitis. A 39-year old patient suffered from fever, polyarthralgia and lumbago. We performed blood culture, from which E. tarda was isolated. Spinal CT scan showed destruction and osteogenesis of the fourth and fifth lumbar vertebral body and cranial CT scan showed destruction of the right lens. So we diagnosed sepsis with pyogenic spondylitis and panophthalmitis. We suspected that chronic ethanol administration reduced the resistance to infection of E. tarda which caused sepsis.

[Effects of morphine and diazepam pretreatment on immobilization stress-induced increase of serotonin metabolism in discrete brain areas of the rat].

Regional concentrations of serotonin (5HT) and 5-hydroxyindoleacetic acid (5HIAA) were measured by high performance liquid chromatography in 16 discrete brain areas of non-stressed control Wistar rats and of stressed Wistar rats. Stress was induced by immobilization for one hour. Also studied were the effects of morphine (10 mg/kg, i.p.) and diazepam (5 mg/kg, i.p.) on concentrations of 5HT and 5HIAA in 10 discrete brain areas of the non-stressed as well as stressed rats. In control rats, regional concentrations of 5HT and 5HIAA varied in the different areas of the prefrontal cortices, limbic structures, striatum and hypothalamus with the highest 5HT contents in the area hypothalamicus lateralis and the lowest in the anterior cingulate cortex. Acute immobilization induced increases in 5HIAA content in prefrontal cortex polar field (FCP), prefrontal cortex medial field (FCM), n. preopticus medialis (PM), area hypothalamicus lateralis (L) and n. dorsomedialis (DM) and also increases in 5HT content in the PM, L, DM, and n. arcuatus median eminence (ARC-ME). In the non-stressed rats, morphine caused an elevation of 5HIAA concentration in the striatum and PM, and also an elevation of 5HT content in the PM and DM, while diazepam induced no alteration in the concentrations of 5HIAA and 5HT. In the stressed rats, morphine potentiated the stress-induced elevation of 5HIAA content in the striatum and attenuated the stress-induced elevation of 5HIAA in the PM and L, and that of 5HT in the PM, remaining 5HIAA content in FCP and FCM unaltered. Diazepam canceled the stress-induced increase in 5HIAA levels in FCP, FCM, CP and DM and in 5HT levels in DM. These results suggest that diazepam may reduce fear and anxiety by attenuating stress-induced increase of serotonin turnover.

Zinc content in discrete hippocampal and amygdaloid areas of the epilepsy (El) mouse and normal mice.

In the present study, zinc content was determined in discrete hippocampal and amygdaloid areas of 3 strains of mice (El, ddY and CBA) using an atomic absorption spectrophotometer. Zinc content was significantly lower in the dentate area of El strain compared to ddY and CBA strains. The El mouse is considered an animal model for epilepsy and the seizures in this mouse appear to originate in the hippocampus. The results suggest the possible involvement of hippocampal zinc in the pathophysiology of convulsive seizures in the epileptic mouse.

[Two cases of papillary tumor of the pancreas].

Two patients with papillary tumors of the pancreas are reported. In both cases, the tumors occurred in women (62 and 60 years of age) who presented with upper abdominal mass and abdominal fullness. The resected tumors were 14 X 16 cm and 13 X 10.5 X 8.3 cm, respectively. Their histology resembled that of the papillary tumor of the pancreas reported by Frantz (1959). The ultrastructural details, including numerous mitochondria, basement membrane and no evidence of secretory or zymogen granules, suggest pancreatic duct cell origin. The first patient died of colon cancer six years and 10 months postoperatively. The second patient is without signs of recurrence five months after resection.

Effect of systemically administered caerulein on dopamine metabolism in rat brain.

The effect of caerulein, a cholecystokinin-like peptide, on the dopamine (DA) system was examined in rat brain. Caerulein, when tested in vitro, had no significant influence on either D-1 or D-2 DA receptors. A single injection of caerulein (400 micrograms/kg, i.p.) reduced both homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatum. No significant change in DA metabolites was found in the other 7 areas (polar and medial fields of prefrontal cortex, anterior cingulate cortex, nucleus accumbens, tuberculum olfactorium, septum and amygdala). After repeated injections of caerulein (200 micrograms/kg, i.p., daily for 5 days), the decreases in striatal HVA and DOPAC had disappeared, while the amount of HVA had increased in the nucleus accumbens. These results suggest that peripherally administered caerulein modulates the nigrostriatal and mesolimbic DA neuron systems in the different modes of action.

Serotonin and 5-hydroxyindoleacetic acid concentrations in individual hypothalamic nuclei and other brain areas of rat.

Serotonin and 5-hydroxyindoleacetic acid (5-HIAA) were measured in individual nuclei of rat hypothalamus and other brain areas using HPLC with electrochemical detection. 5-HIAA levels were first demonstrated in hypothalamic and some discrete brain areas. The 5-HIAA/5-HT ratio was highest in the n. caudatus putamen, high in the n. ventromedialis and lowest in the n. suprachiasmaticus.

Differential effects of acute and chronic administration of haloperidol on homovanillic acid levels in discrete dopaminergic areas of rat brain.

After acute administration of haloperidol, homovanillic acid (HVA) levels were increased in the prefrontal cortex, anterior cingulate cortex, discrete limbic areas and A14 dopamine (DA) neurons. The maximal effect of haloperidol was attained more slowly in the prefrontal cortex and amygdala than in the other regions. The ED50 of haloperidol was 0.03 mg/kg in the prefrontal cortex, but was 0.06-0.07 mg/kg in other areas examined. After repeated administration of haloperidol, tolerance to the HVA increase was observed in the striatum and all limbic areas examined, the amygdala being the most susceptible to this tolerance. In contrast, no tolerance was found in the anteromedial and suprarhinal DA neurons of the prefrontal cortex and A14 DA neurons. These results suggest that the prefrontal cortex may be a possible site for the antipsychotic action of haloperidol. On the other hand, no change of HVA levels in the A12 and A13 DA neurons of the hypothalamus was observed after haloperidol treatments, suggesting a lack of neuronal feedback mechanism in the A12 and A13 DA neurons.