Role of opioid peptides in disorders of attention in psychopathology

Localization and ontogeny of cells expressing preprodynorphin mRNA in the rat cerebral cortex

The regional distribution of preprodynorphin (PPD) mRNA-containing cells (PPD cells) in the rat cerebral cortex was investigated by in situ hybridization histochemistry using a synthetic oligonucleotide probe. In the isocortex, PPD cells were small or medium-sized and were mainly located in layer V. While they were less numerous in the allocortex than in the isocortex. Only a few labeled cells were seen in the piriform and entorhinal cortices. In the hippocampal formation, labeled cells were observed in the granular layer of the dentate gyrus. An ontogenetic study revealed that PPD mRNA-containing cells appeared on postnatal day 7 in the isocortex and the allocortex and on day 14 in the dentate gyrus. Thereafter, they increased in number and signal intensity to reach a plateau on postnatal day 14 in both the isocortex and the allocortex and on day 35 in the dentate gyrus. The time-course of development of PPD mRNA-containing neurons in the cerebral cortex suggested that PPD-derived peptide has a neuromodulator and/or neurotransmitter role in these regions of the brain.

Naltrexone in autistic children: an acute open dose range tolerance trial

The safety and efficacy of naltrexone was explored in an open acute dose range tolerance trial in 10 hospitalized autistic children, ages 3.42 to 6.50 years (mean, 5.04). Naltrexone was given in ascending doses: 0.5, 1.0, and 2.0 mg/kg/day. Behavioral side effects were observed as early as 1/2 hour after dosing. Ratings on the Children's Psychiatric Rating Scale showed that withdrawal was reduced across all three dose levels; administration of 0.5 mg/kg/day dose resulted in increased verbal production; and the 2.0 mg/kg/day dose resulted in reduction of sterotypies. Mild sedation of brief duration was the only side effect. Electrocardiogram, liver function tests, and all other laboratory studies remained unchanged throughout the study. These preliminary findings require replication in a larger sample of patients under double-blind and placebo controlled condition.