[Abnormal patterns of cortical synaptic connectivity in schizophrenia].

Electron microscopic morphometric study of postmortem prefrontal cortex (area 10) and visual cortex (area 17) was performed to estimate the numeric density (Nv) of synapses in layers I and II, neurons in layer II and the number of synapses per neuron in layer II in 20 cases of chronic schizophrenia and 16 healthy controls using stereological physical dissector method. In the prefrontal cortex the Nv of axospinous synapses was significantly lower in layer I (-20%, p < 0.05) in schizophrenia group and in the subgroup with predominantly positive symptoms as compared to controls (p < 0.05). On the contrary, a significantly higher Nv of synapses (+24%, p < 0.05) and the number of synapses per neuron were found in layer II (+42%, p < 0.05) in schizophrenia group and in the subgroups of cases with predominantly negative symptoms and a continuous course of schizophrenia (p < 0.001) as compared to the control group. The subgroup of cases with predominantly negative symptoms displayed a significantly lower number of neurons in layer II of the prefrontal cortex compared to controls (p < 0.05) and the subgroup of cases with predominantly positive symptoms (p < 0.01). In the visual cortex the number of axodendritic synapses per neuron in layer II was significantly higher in schizophrenia, but the other parameters did not differ from those in the control group. These prominent abnormalities of synaptic connectivity might be the structural basis for altered cognitive functions associated with changes in intracortical, cortico-cortical, and cortico-subcortical pathways, and could contribute to the formation of positive and negative symptoms and altered neuronal plasticity in patients with schizophrenia.

[Effect of long-term administration of haloperidol: ultrastructural changes in the prefrontal cortex]. / Deistvie galoperidola pri dlite'lnom vvedenii: u'ltrastrukturnye perestroiki v prefronta'lnoi kore.

Haloperidol, when injected regularly during 3 weeks at a dose of 0.1 mg/kg, influenced glial cells and neuropile. The conditions of the glial cells suggested their increased metabolism. Morphometry revealed increased density of axodendritic synapses and reduced density of axospinal synapses at the spinal collumin the IV layer of medial prefrontal cortex. Virtually all the parameters measured in axodendritic synapses were decreased (presynaptic terminal area, mytochondrial total area and their count in the presynaptic terminal, the length of postsynaptic dense area). The data indicate that ultrastructural changes resulted from decrease of efficiency of synaptic transmission which occurred in several synapses as a result of haloperidol induced receptor block.

[Effect of psychotropic preparations on the properties of tubulin in the brain]. / Vliianie psikhotropnykh preparatov na svoistva tubulina mozga.

Neuroleptics (chlorpromazine, triftazin, haloperidol) inhibited the tubulin polymerization on supernatant of rat brain proteins in vivo at concentrations which corresponded to the therapeutic ones. The electron microscope studies demonstrated that these drugs inhibited the assembly of tubulin in microtubules. As this effect was the same in vivo and in vitro, it was considered specific. Colchicine-binding capacity of tubulin was suppressed only at higher doses of tranquilizers (250 microM). Antidepressant drug melipramine inhibited neither tubulin polymerization in vivo nor its colchicine-binding activity in vivo or in vitro.

[Ultrastructure of the prefrontal cortex in long-term amphetamine administration]. / Ul'trastruktura prefrontal'noi kory mozga pri dlitel'nom vvedenii amfetamina.

In animals three weeks of chronic amphetamine administration at 2.5 mg/kg daily doses elicited either functional or dense-type degenerative changes in nerve cells. The former were prevailing, the latter rarely occurred in the single cells. Morphometric analysis showed sharp density increase in axodendritic synapses and density decrease in axospinal ones at the spine's neck. Apart of this, the postsynaptic dense structures were expanded considerably in axodendritic and axospinal synapses. The authors believe this ultrastructural reorganization to result from the amphetamine-elicited dopaminergic hyperfunction.

[Action of haloperidol on the ultrastructure of areas of the dopaminergic system of the brain]. / Deistvie galoperidola na ul'trastrukturu nekotorykh oblastei dofaminergicheskoi sistemy mozga.

The ultrastructure of the olfactory tubercle was investigated in patients receiving prolonged (3-weeks-long) treatment with low doses (0.1 mg/kg) of haloperidol. This therapy was mostly associated with changes in the neuronal processes and glial cells. It has been found that ultrastructural rearrangement in neurons of the olfactory tubercle is functional in nature which indicates the change in the efficacy of synaptic transmission and in metabolic processes. It is postulated that chronic administration of low doses of haloperidol induces adaptive alterations mediated by DA receptor block.

[Ultrastructure of synapses of the parietal and visceral ganglia of Helix pomatia]. / Ul'trastructura sinapsov parietal'nogo i vistseral'nogo gangliev vinogradnoi ulitki.

Types of synaptic contacts and peculiarities of their distribution in the neuropil of the parietal and visceral ganglia of the edible snail (Helix pomatia) CNS have been studied electron microscopically. Ultrastructure of dendrites and axons has been identified. Dendrites with spinous++ processes, polymorphism of synaptic contacts have been revealed. Besides axo-axonal synapses, axo-dendritic synapses are demonstrated on the trunks and on the spinous processes of the dendrites, as well as dendro-dendritic and serial synapses. Unevenness in distribution of synaptic contacts is shown in the neuropil. The areas of the greatest concentration of the synapses are the "synaptic fields". Peculiarities in distribution of the synaptic contacts are demonstrated in the parietal and visceral ganglia.