Identifying the neural circuitry of alcohol craving and relapse vulnerability

With no further intervention, relapse rates in detoxified alcoholics are high and usually exceed 80% of all detoxified patients. It has been suggested that stress and exposure to priming doses of alcohol and to alcohol-associated stimuli (cues) contribute to the relapse risk after detoxification. This article focuses on neuronal correlates of cue responses in detoxified alcoholics. Current brain imaging studies indicate that dysfunction of dopaminergic, glutamatergic and opioidergic neurotransmission in the brain reward system (ventral striatum including the nucleus accumbens) can be associated with alcohol craving and functional brain activation in neuronal systems that process attentional relevant stimuli, reward expectancy and experience. Increased functional brain activation elicited by such alcohol-associated cues predicted an increased relapse risk, whereas high brain activity elicited by affectively positive stimuli may represent a protective factor and was correlated with a decreased prospective relapse risk. These findings are discussed with respect to psychotherapeutic and pharmacological treatment options.     

Dopamine D1 receptors in human parathyroid gland: In vitro and in vivo studies

Dopamine receptors in human parathyroid were studied in vitro using ligand binding techniques. With 3H-piflutixol as ligand, binding characteristic of the dopamine D1 receptor was observed. Administration of apomorphine, flupenthixol or metoclopramide to normal controls or acute schizophrenic patients at doses producing significant alterations in serum prolactin concentrations did not alter serum parathyroid hormone (PTH) concentrations. Whilst D1 binding sites are present in human parathyroid, the measurement of PTH after administration of dopaminergic drugs is unlikely to provide a test of D1 receptor function in man.     

Orexin A in the ventral tegmental area induces conditioned place preference in a dose-dependent manner: Involvement of D1/D2 receptors in the nucleus accumbens

It has been shown that orexin A in the ventral tegmental area (VTA) is necessary for development of morphine place preference. Additionally, D1 and D2 dopamine receptors in the nucleus accumbens (NAc) have critical roles in motivation and reward. However, little is known about the function of orexin in conditioned place preference (CPP) in rats and involvement of D1/D2 receptors in the NAc. In the present study, we investigated the effect of direct administration of orexin A into the VTA, and examined the role of intra-accumbal dopamine receptors in development (acquisition) of reward-related behaviors in the rats. Adult male Wistar rats were unilaterally implanted by two separate cannulae into the VTA and NAc. The CPP paradigm was used, and, conditioning score and locomotor activity were recorded by Ethovision software. The results showed that unilateral intra-VTA administration of orexin A (27, 53 and 107ng/0.3μl saline) during conditioning phase induced CPP in a dose-dependent manner. The most effective dose of intra-VTA orexin-A in eliciting CPP was 107ng. However, intra-NAc administration of SCH 23390 (0.25, 1 and 4μg/0.5μl saline), a D1 receptor antagonist, and sulpiride (0.25, 1 and 4μg/0.5μl DMSO), a D2 receptor antagonist, inhibited the development of orexin-induced CPP. The inhibitory effect of D2 but not D1 receptor antagonist was exerted in a dose-dependent manner. It is supposed that the activation of VTA dopaminergic neuron by orexin impresses the D2 receptors more than D1 receptors in the NAc.     

Binding and uptake of MPTP by preparations of human and animal brain

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to cause parkinsonism in man and animals, producing acute behavioral effects within minutes of administration. This syndrome has been attributed to specific effects on dopaminergic systems. MPTP blocked the binding of haloperidol to membranes from rat and human brain (IC₅₀ = 2.5 μM), but it did not block the binding of flupenthixol to these membranes. These results indicate that MPTP is a ligand for D-2 dopamine receptors but not for D-1 dopamine receptors. Synaptosomes from rat, mouse or guinea-pig corpus striatum or from monkey caudate nucleus exhibited little ability to take up MPTP from the incubation medium. The synaptosomes took up at least 20–50 times more dopamine than MPTP. These results indicate that MPTP could cause acute effects by binding to dopamine receptors and that the specific toxicity MPTP exerts for dopaminergic neuron is not primarily based on the specific uptake of MPTP into these neurons.     

A sensitive and specific radioimmunoassay for cis (Z)-flupenthixol in human serum

The injection of cis (Z)-7-carboxy-flupenthixol covalently bound to bovine serum albumin into a sheep has produced an antibody serum which can be used in a very high dilution. This antibody serum and tritium labelled cis (Z)-flupenthixol of high specific activity have been used for a radioimmunoassay for cis (Z)-flupenthixol. The radioimmunoassay has a limit of sensitivity of about 0.3 ng/ml serum or plasma. Some cross-reactivity was seen with trans(E)-flupenthixol, flupenthixol metabolites and cis (Z)-flupenthixol esters, but this did not influence the estimation of cis (Z)-flupenthixol to any significant degree. A series of drugs structurally related to flupenthixol showed varying degrees of cross-reactivity depending on the closeness of their relationship to flupenthixol. Compounds of other therapeutic groups, which structurally are un-related to flupenthixol, showed very little cross-reactivity. The standard deviation was 6–7 per cent when a series of identical samples of pooled patient sera was estimated. Oral administration of cis (Z)-flupenthixol to human volunteers indicates a rather slow absorption with maximum serum level 6 hours after administration. Intramuscular injection of flupenthixol decanoate in Viscoleo to patients gives serum concentration curves, which show maxima 7 days after injection and a factor of two fluctuation in serum level in a two weeks dosage interval.     

Adolescent Maturation of Dopamine D1 and D2 Receptor Function and Interactions in Rodents

Adolescence is a developmental period characterized by heightened vulnerability to illicit drug use and the onset of neuropsychiatric disorders. These clinical phenomena likely share common neurobiological substrates, as mesocorticolimbic dopamine systems actively mature during this period. Whereas prior studies have examined age-dependent changes in dopamine receptor binding, there have been fewer functional analyses. The aim of the present study was therefore to determine whether the functional consequences of D1 and D2-like activation are age-dependent. Adolescent and adult rats were given direct D1 and D2 agonists, alone and in combination. Locomotor and stereotypic behaviors were measured, and brains were collected for analysis of mRNA expression for the immediate early genes (IEGs), cfos and arc. Adolescents showed enhanced D2-like receptor control of locomotor and repetitive behaviors, which transitioned to dominant D1-like mechanisms in adulthood. When low doses of agonists were co-administered, adults showed supra-additive behavioral responses to D1/D2 combinations, whereas adolescents did not, which may suggest age differences in D1/D2 synergy. D1/D2-stimulated IEG expression was particularly prominent in the bed nucleus of the stria terminalis (BNST). Given the BNST’s function as an integrator of corticostriatal, hippocampal, and stress-related circuitry, and the importance of neural network dynamics in producing behavior, an exploratory functional network analysis of regional IEG expression was performed. This data-driven analysis demonstrated similar developmental trajectories as those described in humans and suggested that dopaminergic drugs alter forebrain coordinated gene expression age dependently. D1/D2 recruitment of stress nuclei into functional networks was associated with low behavioral output in adolescents. Network analysis presents a novel tool to assess pharmacological action, and highlights critical developmental changes in functional neural circuitry. Immature D1/D2 interactions in adolescents may underlie their unique responses to drugs of abuse and vulnerability to psychopathology. These data highlight the need for age-specific pharmacotherapy design and clinical application in adolescence.     

Chromosomal localization of three human D5 dopamine receptor genes

It is currently thought that genetic predisposition to imbalances in dopaminergic transmission may underlie several neurological disorders, including schizophrenia, manic depression, Tourette syndrome, Parkinson disease, Huntington disease, and alcohol abuse. Originally two receptors, D1 and D2, were thought to account for all of the pharmacological actions of dopamine. However, through homology screening three additional genes, D3, D4, and D5, and two pseudogenes closely related to D5 have been characterized. To begin our genomic and evolutionary analyses of the human D5 dopamine receptor gene and its two pseudogenes, we have mapped each of them to their respective chromosomes. By combining in situ hybridization results with sequence analysis of PCR products from microdissected chromosomes, somatic cell hybrids, and radiation hybrids, we have assigned DRD5 (the locus containing the functional human D5 receptor gene) to chromosome 4p16.1, DRD5P1 (the locus containing D5 pseudogene 1) to chromosome 2p11.1-p11.2, and DRD5P2 (the locus of D5 pseudogene 2) to chromosome 1q21.1.     

Stimulatory Effect of the D2 Antagonist Sulpiride on Glucose Utilization in Dopaminergic Regions of Rat Brain

Local cerebral glucose utilization (LCGU) was measured, using the quantitative autoradiographic [14C]2-deoxy-D-glucose method, in 56 brain regions of 3-month-old, awake Fischer-344 rats, after intraperitoneal administration of sulpiride (SULP) 100 mg/kg. SULP, an "atypical" neuroleptic, is a selective antagonist of D2 dopamine receptors. LCGU was reduced in a few nondopaminergic regions at 1 h after drug administration. Thereafter, SULP progressively elevated LCGU in many other regions. At 3 h, LCGU was elevated in 23% of the regions examined, most of which are related to the CNS dopaminergic system (caudate-putamen, nucleus accumbens, olfactory tubercle, lateral habenula, median eminence, paraventricular hypothalamic nucleus). Increases of LCGU were observed also in the suprachiasmatic nucleus, lateral geniculate, and inferior olive. These effects of SULP on LCGU differ from the effects of the "typical" neuroleptic haloperidol, which produces widespread decreases in LCGU in the rat brain. Selective actions on different subpopulations of dopamine receptors may explain the different effects of the two neuroleptics on brain metabolism, which correspond to their different clinical and behavioral actions.     

Neuroadaptations to hyperdopaminergia in dopamine D3 receptor-deficient mice

The dopamine D3 receptor (D3R) has been implicated in schizophrenia, drug addiction, depression and Parkinson's disease. The D3R is localized post-synaptically on nucleus accumbens neurons, but is also an autoreceptor on dopaminergic neurons in the mesencephalon. Its functional role as autoreceptor is highly debated, but supported by the elevated basal extracellular dopamine levels found in D3R-deficient mice. To investigate the functional role of the D3R in vivo, we used mice with a targeted disruption of the D3R gene. We found a higher basal level of grooming in D3R-deficient mice, compared to their wild-type littermates. This behavior, which is under the control of D1R stimulation, may be related to an increased dopaminergic tone, since no changes in the gene expression of dopamine D1 and D2 receptors were noticed in the striatum of these mice. D3R-deficient mice displayed other neuroadaptive changes, including decreased tyrosine hydroxylase, increased dopamine transporter mRNAs and increased dopamine reuptake in striatum. The level of tyrosine hydroxylase protein was unchanged in the striatum, as preprodynorphin and preproenkephalin gene expressions. All the changes identified in D3R-deficient mice cannot explain hyperdopaminergia, but, on the contrary, tend to attenuate this phenotype. These results support a distinct role for D2R and D3R as autoreceptors: the D2R is the release-regulating and firing rate-regulating autoreceptor, whereas the D3R may control basal dopamine levels in the striatum, by an unknown mechanism, which does not involve regulation of dopamine transporters or tyrosine hydroxylase. This hyperdopaminergia phenotype of D3R-deficient mice may explain their hyperactivity to drug-paired environmental cues.     

Role of Neostriatal Dopamine D1 and D2 Receptors in the Organization of Neuronal Activity in the Entopeduncular Nucleus

In chronic experiments on cats, we studied the effects of selective blockade of the dopamine D1 and D2 receptors in the nucleus caudatus (NC) against the background neuronal activity (BA) in the entopeduncular nucleus (ENT) and on the responses of these neurons evoked by stimulation of the subthalamic nucleus (STN). A blocker of D1 receptors, SCH 23390, and sulpiride, a blocker of D2 receptors, when injected into the NC head, led to changes in the BA frequency. The direction of these effects was different: blockade of the D2 receptors evoked a significant decrease in the BA frequency of ENT neurons, but when the D2 receptors were blocked, a trend toward an increase in this frequency was observed. Some of the ENT cells demonstrated similar changes in the temporal organization of their impulse activity with blockade of the D1 and D2 receptors. Namely, besides single action potentials (AP), high-frequency burst discharges began to be generated. Blockade of both D1 and D2 receptors prolonged the responses of ENT neurons to STN stimulation due to the appearance of similar AP bursts, while control animals demonstrated reactions consisting of solely single AP. The question on a dual (synergic and antagonistic) involvement of the neostriatal D1 and D2 receptors in the dopaminergic regulation of the basal ganglia is under discussion.     

Comparison of brain activity between dopamine D2 receptor-knockout and wild mice in response to dopamine agonist and antagonist assessed by fMRI

It has been reported that antipsychotic dopamine-D2-receptor (D2R) antagonists affected other neurotransmitter systems. In the present study, the effects of a D2R agonist, bromocriptine, and a D2R antagonist, spiperone, on brain activity were investigated using wild-type mice (WT) with intact D2Rs, and D2R-knockout mice (D2R-KO) lacking D2Rs by functional magnetic resonance imaging. In the WT, flow-weighted signal intensity significantly increased after administration of bromocriptine in the hippocampal formation. In contrast, signal intensity significantly decreased after administration of spiperone in the somatosensory-motor cortices, thalamus, anterior cingulate cortex, caudate-putamen, nucleus accumbens, hippocampal formation, and amygdala. In the D2R-KO, however, no significant changes were observed after administration of either bromocriptine or spiperone. The present results indicated that the D2R-KO lacked sensitivity to D2R agonist and antagonist in agreement with its genetic defects, which confirmed that the changes in brain activity in the WT after administration of either drug were mediated through D2Rs. These results suggest that antipsychotic D2R antagonists affect activity of the same brain regions of human patients through D2Rs, as observed in the present study. These changes in brain activity might be related to therapeutic efficacy as well as side effects of antipsychotic drugs on schizophrenic patients.     

Differential regulation of dopamine D1 and D2 signaling by nicotine in neostriatal neurons

Nicotine, acting on nicotinic acetylcholine receptors (nAChRs) expressed at pre-synaptic dopaminergic terminals, has been shown to stimulate the release of dopamine in the neostriatum. However, the molecular consequences of pre-synaptic nAChR activation in post-synaptic neostriatal neurons are not clearly understood. Here, we investigated the effect of nAChR activation on dopaminergic signaling in medium spiny neurons by measuring phosphorylated DARPP-32 (dopamine- and cAMP-regulated phosphoprotein of Mr 32 kDa) at Thr34 (the PKA-site) in mouse neostriatal slices. Nicotine produced dose-dependent responses, with a low concentration (1 microm) causing a sustained decrease in DARPP-32 Thr34 phosphorylation and a high concentration (100 microm) causing a transient increase in DARPP-32 Thr34 phosphorylation. Depending on the concentration of nicotine, either dopamine D2 or D1 receptor signaling was predominantly activated. Nicotine at a low concentration (1 microm) activated dopamine D2 receptor signaling in striatopallidal/indirect pathway neurons, likely by activating alpha4beta2* nAChRs at dopaminergic terminals. Nicotine at a high concentration (100 microm) activated dopamine D1 receptor signaling in striatonigral/direct pathway neurons, likely by activating (i) alpha4beta2* nAChRs at dopaminergic terminals and (ii) alpha7 nAChRs at glutamatergic terminals, which, by stimulating the release of glutamate, activated NMDA/AMPA receptors at dopaminergic terminals. The differential effects of low and high nicotine concentrations on D2- and D1-dependent signaling pathways in striatal neurons may contribute to dose-dependent actions of this drug of abuse.     

Effects of the stimulation of D1 and D2 dopaminergic receptors on the electrically induced release of gamma-(3H)-aminobutyric acid in the prefrontal cortex of the rat

The effects of D1 and D2 dopaminergic agonists and antagonists on the electrically-evoked release of gamma-[3H] aminobutyric acid (3H-GABA) have been studied on rat prefrontal cortex slices. The major part of the electrically-evoked release of 3H-GABA appeared to be Ca++ dependent since a 62% decrease was observed when calcium was removed from the superfusion medium. Two specific D2 dopaminergic agonists, RU 24926 (10(-7) M) and lisuride (10(-6) M), respectively induced a 32% and a 50% inhibition of the electrically-evoked release of 3H-GABA. The selective D2 dopaminergic antagonists sulpiride (10(-5) M) totally abolished the effect of RU 24926 and partially abolished the effect of lisuride. The selective D1 agonist SKF 38393 (10(-5) M) did not affect 3H-GABA release. These results suggest that in the rat prefrontal cortex in vitro, the dopaminergic modulation of 3H-GABA release is mediated through D2 but not D1 receptors. The activation of D2 dopaminergic receptors induces an inhibition of the electrically-evoked release of 3H-GABA.     

Repeated alcohol administration during adolescence causes changes in the mesolimbic dopaminergic and glutamatergic systems and promotes alcohol intake in the adult rat

Adolescence is a developmental period which the risk of drug and alcohol abuse increases. Since mesolimbic dopaminergic system undergoes developmental changes during adolescence, and this system is involved in rewarding effects of drugs of abuse, we addressed the hypothesis that ethanol exposure during juvenile/adolescent period over-activates mesolimbic dopaminergic system inducing adaptations which can trigger long-term enduring behavioural effects of alcohol abuse. We treated juvenile/adolescent or adult rats with ethanol (3 g/kg) for two-consecutive days at 48-h intervals over 14-day period. Here we show that intermittent ethanol treatment during the juvenile/adolescence period alters subsequent ethanol intake. In vivo microdialysis demonstrates that ethanol elicits a similar prolonged dopamine response in the nucleus accumbens of both adolescent and adult animals pre-treated with multiple doses of ethanol, although the basal dopamine levels were higher in ethanol-treated adolescents than in adult-treated animals. Repeated ethanol administration also down-regulates the expression of DRD2 and NMDAR2B phosphorylation in prefrontal cortex of adolescent animals, but not of adult rats. Finally, ethanol treatment during adolescence changes the acetylation of histones H3 and H4 in frontal cortex, nucleus accumbens and striatum, suggesting chromatin remodelling changes. In summary, our findings demonstrate the sensitivity of adolescent brain to ethanol effects on dopaminergic and glutamatergic neurotransmission, and suggest that abnormal plasticity in reward-related processes and epigenetic mechanisms could contribute to the vulnerability of adolescents to alcohol addiction.     

The role of D1 and D2 dopamine receptors of the rat nucleus accumbens in immunostimulation

The analysis of the immune response changes in Wistar rats has shown that bilateral electrolytic lesions of the nucleus accumbens characterized by a high density of D1 an D2 dopamine (DA) receptors resulted in a decrease of the immune response to SRBC. Administration of selective agonists of D1 and D2 DA receptors to sham-operated animal: 20 mg/kg of SKF 38393 or 1.0 mg/kg of quinpirol, respectively, produced significant enhancement of plaque- and rosette-formation. However, the immune response level in the damaged rats did not increase following quinpirol administration, but was maintained at control values, rather. At the same time, activation of D1 DA receptors in rats with destructed nucleus accumbens did not affect the immune response level as compared to that of sham-operated animals receiving SKF 38393. The data obtained give evidence of involvement of D2 DA receptors of the nucleus accumbens in immunomodulation, although D2 DA receptors of other brain structures may also contribute to this process. D1 DA receptors of this localization seem not to play any important role in the immune response control.     

Bone effects of vitamin D - Discrepancies between in vivo and in vitro studies

Vitamin D was discovered as an anti-rachitic agent, but even at present, there is no direct evidence to support the concept that vitamin D directly stimulates osteoblastic bone formation and mineralization. It appears to be paradoxical, but vitamin D functions in the process of osteoclastic bone resorption. In 1952, Carlsson reported that administration of vitamin D(3) to rats fed a vitamin D-deficient, low calcium diet raised serum calcium levels. Since the diet did not contain appreciable amounts of calcium, the rise in serum calcium was considered to be derived from bone. Since then, this assay has been used as a standard bioassay for vitamin D compounds. Osteoclasts, the cells responsible for bone resorption, develop from hematopoietic cells of the monocyte-macrophage lineage. Several lines of evidence have shown that the active form of vitamin D(3), 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2)D(3)] is one of the most potent inducers of receptor activator of NF-κB ligand (RANKL), a key molecule for osteoclastogenesis, in vitro. In fact, 1α,25(OH)(2)D(3) strongly induced osteoclast formation and bone resorption in vitro. Nevertheless, 1α,25(OH)(2)D(3) and its prodrug, Alfacalcidol (1α-hydroxyvitamin D(3)) have been used as therapeutic agents for osteoporosis since 1983, because they increase bone mineral density and reduce the incidence of bone fracture in vivo. Furthermore, a new vitamin D analog, Eldecalcitol [2β-(3-hydroxypropoxy)-1α,25(OH)(2)D(3)], has been approved as a new drug for osteoporosis in Japan in January 2011. Interestingly, these beneficial effects of in vivo administration of vitamin D compounds are caused by the suppression of osteoclastic bone resorption. The present review article describes the mechanism of the discrepancy of vitamin D compounds in osteoclastic bone resorption between in vivo and in vitro.     

Striatal Dopamine D2/3 Receptor Availability in Treatment Resistant Depression

Several studies demonstrated improvement of depressive symptoms in treatment resistant depression (TRD) after administering dopamine agonists which suggest abnormal dopaminergic neurotransmission in TRD. However, the role of dopaminergic signaling through measurement of striatal dopamine D_2/3 receptor (D2/3R) binding has not been investigated in TRD subjects. We used [¹²³I]IBZM single photon emission computed tomography (SPECT) to investigate striatal D2/3R binding in TRD. We included 6 severe TRD patients, 11 severe TRD patients on antipsychotics (TRD AP group) and 15 matched healthy controls. Results showed no significant difference (p = 0.75) in striatal D2/3R availability was found between TRD patients and healthy controls. In the TRD AP group D2/3R availability was significantly decreased (reflecting occupancy of D2/3Rs by antipsychotics) relative to TRD patients and healthy controls (p<0.001) but there were no differences in clinical symptoms between TRD AP and TRD patients. This preliminary study therefore does not provide evidence for large differences in D2/3 availability in severe TRD patients and suggests this TRD subgroup is not characterized by altered dopaminergic transmission. Atypical antipsychotics appear to have no clinical benefit in severe TRD patients who remain depressed, despite their strong occupancy of D2/3Rs.     

Low digit ratio 2D:4D in alcohol dependent patients

The ratio of the lengths of the second and fourth finger (2D∶4D) has been described as reflecting the degree of prenatal androgen exposure in humans. 2D∶4D is smaller for males than females and is associated with traits such as left-handedness, physical aggression, attention-deficit-hyperactivity disorder and a genetic polymorphism of the androgen receptor. All of these traits are known to be correlated to the vulnerability for alcohol dependency. We therefore hypothesized low 2D∶4D in patients with alcohol dependency. In the present study on 131 patients suffering from alcohol dependency and 185 healthy volunteers, we found that alcohol dependent patients had smaller 2D∶4D ratios compared to controls with preserved sexual dimorphism but with reduced right-left differences. The detection of alcohol dependency based on 2D∶4D ratios was most accurate using the right hand of males (ROC-analysis: AUC 0.725, sensitivity 0.667, specificity 0.723). These findings provide novel insights into the role of prenatal androgen exposure in the development of alcohol dependency and for the use of 2D∶4D as a possible trait marker in identifying patients with alcohol dependency.     

Effect of apoptosis proteins on function of vasopressin- and dopaminergic hypothalamic neurons

To study character of effect of apoptosis signal proteins on activities of neurosecretory cells and neurons of rat hypothalamus, pharmacologic inhibitors of proapoptotic protein p53 Pifithrin-alpha and antiapoptotic protein Bcl-2 HA14-1 were injected into the hypothalamus. Activation of vasopressinergic neurosecretory cells at administration of the blocker Bcl-2 HA14-1 was shown: there were observed an increase of vasopressin mRNA in neurons of hypothalamus supraoptical and paraventricular nuclei, a decrease of the immunoreactive vasopressin content in posterior pituitary, and reduction of diuresis. Inactivation of p53 inhibited release of vasopressin from hypothalamus cell bodies, which is indicated by an elevated content of immunoreactive vasopressin in neurosecretory cell bodies with its unchanged synthesis, a decrease of the neurohormone content in the posterior pituitary, and an increase of diuresis rate. Activation of vasopressinergic neurons of the suprachiasmatic nucleus was also shown. Administration of the blocker Bcl-2 has been revealed to decrease functional activity both of dopaminergic neurons (Zona Incerta) and of dopaminergic neurosecretory cells (arcuate nucleus), in which a decrease of the tyrosine hydroxylase content was observed. The p53 inactivation also led to a decrease of activity of dopaminergic neurosecretory cells of arcuate nucleus, whereas activity of the proteins Zone Incerta did not change. Thus, it has been shown that a change of the apoptotic protein content in vasopressinergic and dopaminergic neurons and neurosecretory cells leads to a change of their functional activity, the character and possibly mechanisms of effects of apoptotic proteins on activities of vasopressin- and dopaminergic cells being different.