Neuropeptides in dopamine-containing regions of the brain

This paper reviews evidence of direct interactions occurring in the central nervous system between peptide- and dopamine-containing neural networks. While it seems fairly clear that neuropeptides are involved in the process of interneuronal communication, their specific role appears to be different from that of classic transmitters (which include dopamine). Neuropeptides coexist with dopamine in specific dopamine-containing neurons; in addition they interact abundantly with the dopaminergic neurons, by acting either on the perikarya or on the dopaminergic nerve terminals. Such interactions are reciprocal and account for some behavioral correlates of neuropeptide and dopamine alterations in the brain. They also shed new light on the pathophysiology of neurological and psychiatric diseases associated with depletion or abundance of brain peptides

Organization of central nervous system dopaminergic pathways

In the present paper the organization of central nervous system dopaminergic pathways is concisely reviewed. Six dopaminergic systems are described: the midbrain efferent system, the tubero-infundibular, the diencephalo-spinal, the incerto-hypothalamic, the periventricular, and the retinal systems. Anatomo-functional correlations can be presently outlined for most dopamine-containing networks, and anatomo-clinical studies indicate that they are globally affected in patients suffering from Parkinson's disease

Can trazodone induce parkinsonism?

trazodone induce parkinsonism

Cholinergic and non-cholinergic forebrain projections to the interpeduncular nucleus

A combined fluorescent retrograde tracing and acetylcholinesterase (AChE) histochemical technique was used for the study of some forebrain projections to the interpeduncular nucleus (IPN). After injections of a fluorescent tracer into the IPN, the distribution of AChE-containing and of fluorescent retrogradely labeled neurons was simultaneously studied in the habenular nuclei, medial septum and diagonal band of Broca. In all these regions, the majority of retrogradely labeled neurons also contained AChE: neurons located in the habenular nuclei stained lightly or moderately for the enzyme, while neurons located in the diagonal band and medial septum displayed intense AChE staining and were classified as putatively cholinergic perikarya. In all regions, a minority of labeled neurons did not stain for AChE, and were identified as non-cholinergic neurons projecting to the IPN. The present study shows the existence of a biochemical heterogeneity in the habenulo-interpeduncular and telencephalo-interpeduncular pathways, and indicates that the latter contains putatively cholinergic as well as non-cholinergic fibers

Histochemical demonstration of heavy metals in the reptilian archicortex

The topographic distribution of heavy metals has been studied in the reptilian brain by means of Timm's sulphide silver method. Timm-positive histochemical reaction was detected in the archicortex and in the septum. In the first region, the staining pattern yielded evidence of cortical layering and the distribution of mossy fiber terminals. In the septum, uneven distribution of histochemical staining permitted identification of different functional territories. These data show that the reptilian archicortex is in many ways homologous to the mammalian hippocampus and fascia dentata, and also indicate that it undergoes significant remodeling during evolution

A genetic study of neostriatal cholinergic neurones in C57BL/6 and DBA/2 mice

In the present study Butcher's pharmaco-histochemical technique for acetylcholinesterase has been employed for a morphometrical analysis of striatal cholinergic neurones in crossbred C57BL/6 x DBA/2 F1 mice. The general organization of neostriatal cholinergic systems in hybrid mice was similar to that of parent strains. However, as shown by morphometry, the size of neostriatum in hybrids was larger than that of both parental strains, and the density of striatal cholinergic neurones was significantly lower than that of DBA/2 mice, being close to that of the C57BL/6 strain. The present data indicate that a reduced number of striatal cholinergic neurones is inherited as a dominant trait by these hybrid mice

Quantitative pharmacohistochemistry of acetylcholinesterase in neostriatum of inbred strains of mice

A quantitative pharmacohistochemical technique has been used in the present study to assay acetylcholinesterase (AChE) activity in the neostriatum of C57BL/6 and DBA/2 mice. This technique permits the measurement of enzyme activity into microscopically defined compartments and is suitable for the study of striatal AChE-containing, putatively cholinergic, neurons. Microphotometric measurements have been performed in the cytoplasm of AChE-containing perikarya and in the striatal matrix: in both compartments, AChE activity was significantly higher in DBA/2 than in C57BL/6 mice. The present data show that AChE quantitative pharmacohistochemistry is suitable for studying the enzyme activity in nervous tissue and, particularly, in the cytoplasm of individual AChE-containing neurons. In addition, interstrain comparison indicates the presence of a genetically determined higher AChE content in striatal neurons of the DBA/2 strain

An investigation of hearing impairment in de-novo Parkinson's disease patients: A preliminary study

To investigate the peripheral auditory pathway in Parkinson's disease (PD) by using objective, quantitative and non-invasive audiological techniques, transient-evoked (TEOAE) and distortion product (DPOAE) otoacoustic emissions, in order to detect subclinical alterations of cochlear functioning and possible changes after dopaminergic stimulation