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H Caruncho

Publications and source records attributed to H Caruncho.

4 recordsLinked to original sources
PubMed1998

A decrease of reelin expression as a putative vulnerability factor in schizophrenia.

Postmortem prefrontal cortices (PFC) (Brodmann's areas 10 and 46), temporal cortices (Brodmann's area 22), hippocampi, caudate nuclei, and cerebella of schizophrenia patients and their matched nonpsychiatric subjects were compared for reelin (RELN) mRNA and reelin (RELN) protein content. In all of the brain areas studied, RELN and its mRNA were significantly reduced (approximately 50%) in patients with schizophrenia; this decrease was similar in patients affected by undifferentiated or paranoid schizophrenia. To exclude possible artifacts caused by postmortem mRNA degradation, we measured the mRNAs in the same PFC extracts from gamma-aminobutyric acid (GABA)A receptors alpha1 and alpha5 and nicotinic acetylcholine receptor alpha7 subunits. Whereas the expression of the alpha7 nicotinic acetylcholine receptor subunit was normal, that of the alpha1 and alpha5 receptor subunits of GABAA was increased when schizophrenia was present. RELN mRNA was preferentially expressed in GABAergic interneurons of PFC, temporal cortex, hippocampus, and glutamatergic granule cells of cerebellum. A protein putatively functioning as an intracellular target for the signal-transduction cascade triggered by RELN protein released into the extracellular matrix is termed mouse disabled-1 (DAB1) and is expressed at comparable levels in the neuroplasm of the PFC and hippocampal pyramidal neurons, cerebellar Purkinje neurons of schizophrenia patients, and nonpsychiatric subjects; these three types of neurons do not express RELN protein. In the same samples of temporal cortex, we found a decrease in RELN protein of approximately 50% but no changes in DAB1 protein expression. We also observed a large (up to 70%) decrease of GAD67 but only a small decrease of GAD65 protein content. These findings are interpreted within a neurodevelopmental/vulnerability "two-hit" model for the etiology of schizophrenia.

Age of Onset↗
PubMed1996

Modifications of gamma-aminobutyric acidA receptor subunit expression in rat neocortex during tolerance to diazepam.

We evaluated whether tolerance to the antagonism of bicuculine-induced seizures by diazepam is associated with changes (i) in the content of mRNAs encoding for gamma-aminobutyric acidA (GABAA) receptor subunits, (ii) in the expression density of these subunits, and (iii) in the 1,4-benzodiazepine binding site characteristics in discrete neocortical structures. We found that in diazepam-tolerant rats, the content of the mRNA encoding for the alpha 1 subunit of the GABAA receptor decreased in the frontoparietal motor (FrPaM) cortex and in the hippocampus (42% and 20%, respectively) but not in the frontoparietal somatosensory (FrPaSS) cortex, striatum, olfactory bulb, and cerebellum. In the FrPaM cortex, gamma 2S and gamma 2L subunit mRNA contents were also decreased (48% and 30%, respectively), whereas that of alpha 5 was increased (30%). In the FrPaM and FrPaSS cortices as well as in cerebellum of diazepam-tolerant rats, the content of alpha 2, alpha 3, alpha 6, beta 2, and delta subunit mRNA was unchanged, as was the content of alpha 2, alpha 5, gamma 1, and gamma 2S subunit mRNA in the hippocampus. Furthermore, the reduction in alpha 1 subunit mRNA content in the FrPaM cortex and the anticonvulsant tolerance to diazepam returned to control values 72 hr after termination of the protracted diazepam treatment. Rats receiving a treatment with imidazenil in doses equipotent and with a schedule identical to that of diazepam failed to exhibit tolerance to the anticonvulsant action of this drug or cross-tolerance to diazepam. In these rats, the content of mRNA encoding for alpha 1, alpha 2, alpha 3, alpha 5, alpha 6, gamma 1, gamma 2S, gamma 2L, and delta GABAA receptor subunits failed to change in the FrPaM and FrPaSS cortices, in the hippocampus, and in the other brain areas that were studied in diazepam-tolerant rats. Although the density and affinity of [3H]flumazenil and [3H]imidazenil binding failed to change in the FrPaM and FrPaSS cortices of diazepam-tolerant rats, the expression density of alpha 1 subunit immunogold labeling decreased by 37%, whereas that of alpha 5, gamma 2L/S, and beta 2/3 increased by 158%, 50%, and 47%, respectively, in the FrPaM cortex, and the density of the alpha 5 subunit selectively increased (209%) in the FrPaSS cortex. In contrast, the immunogold labeling density of the alpha 1, alpha 5, gamma 2L/S, and beta 2/3 subunits failed to change in either the FrPaM or FrPaSS cortex of rats receiving protracted imidazenil treatment.

Animals↗
PubMed1988

Monoaminergic systems of the hypothalamus of ten amphibian species: a histofluorescence study.

The morphological features and distribution of monoamine (MA) containing neurons in the hypothalamus of ten amphibian species have been studied using two histofluorescence methods. Three hypothalamic MA containing nuclei were demonstrated in all species: preoptic recess organ (PRO), paraventricular organ (PVO) and nucleus infundibularis dorsalis (NID), all three composed of liquor-contacting (LC) and accompanying MA neurons. The PRO, more developed in anuran species, shows LC neurons of variable morphology among species which are arranged in layers bordering the preoptic recess. In anurans the PRO extends into the walls of the unpair telencephalic ventricle. The PVO, well developed in all amphibians studied, has bipolar LC neurons with sometimes branched apical dendrites and basal axons. The NID is fairly well developed and better delimited from the PVO in urodeles than in anurans. MA containing fibres of the hypothalamus are specially abundant in the lateral forebrain bundle and the lateral area of the PVO.

Amphibians↗