Recent findings on the organization of central nervous system structures involved in the innervation of endocrine glands and other organs; observations obtained by the transneuronal viral double-labeling technique.

This review summarizes the data obtained with the aid of the recently introduced dual viral tracing technique, which uses isogenic recombinants of pseudorabies virus that express unique reporter gene. This approach made possible to explore simultaneously neural circuits of two organs. The results of these studies indicate: (1) there are neurons innervating exclusively a given organ; (2) left-sided predominance in the supraspinal innervation of the endocrine glands (adrenal, ovary) studied, so far; (3) viral co-infection of neurons, i.

Cerebral neurons involved in the innervation of both the adrenal gland and the ovary: a double viral tracing study.

Previous studies using the viral transneuronal tracing technique demonstrated central autonomic circuits involved in the innervation of the adrenal gland and the ovary. Since the pattern of infection of central nervous system structures is similar after virus inoculation of the adrenal gland and the ovary, and, on the other hand, it is well documented that the activity of the hypothalamo-pituitary-adrenal axis exerts an inhibitory effect on the reproductive system, we investigated whether there are neurons that are transneuronally connected both with the adrenal gland and the ovary. The central circuitry involved in the innervation of the left adrenal and the left ovary was studied in individual rats by dual transneuronal tracing using isogenic recombinant strains (BDG and DS-RED) of Bartha strain of pseudorabies virus.

Location of parotid preganglionic neurons in the inferior salivatory nucleus and their relation to the superior salivatory nucleus of rat.

In major brain maps the location of the salivatory nuclei of the rat is depicted from the level of the root of the facial nerve to the level of the rostral tip of the nucleus of the solitary tract. Most published data deal with the superior salivatory nucleus (SSN). In the present study the topography of the parasympathetic preganglionic neurons of the inferior salivatory nucleus (ISN) that innervate the parotid gland through the otic ganglion was determined by means of a retrograde transneuronal labeling technique.

Transneuronal retrograde viral labeling in the brain stem and hypothalamus is more intense from the left than from the right adrenal gland.

Previous studies using the viral transneuronal tracing technique demonstrated central autonomic circuits involved in the innervation of the adrenal gland. Since increasing number of data indicate laterality in the neuroendocrine system, we aimed to investigate whether the supraspinal innervation of the adrenal gland exhibits asymmetry or not. The central circuitry involved in the innervation of the left and the right adrenal gland was studied in individual rats by dual transneuronal tracing using isogenic recombinant strains (Ba-DupGreen and Ba-Duplac expressing lacZ) of Bartha strain of pseudorabies virus.

The supraspinal innervation of the left adrenal is more intense than that of the right one.

Background And Purpose: Previous studies using the viral transneuronal tracing technique demonstrated that central autonomic circuits are involved in the innervation of the adrenal gland. Since increasing number of data indicate laterality in the neuroendocrine system, we aimed to investigate whether the supraspinal innervation of the adrenal gland exhibits asymmetry or not.

Methods: The central circuitry involved in the innervation of the left and the right adrenal gland was studied in individual rats by dual transneuronal tracing using isogenic recombinant strains (BDG and BDL) of Bartha strain of pseudorabies virus.

Predominance of supraspinal innervation of the left ovary.

In our previous studies using the viral transneuronal tracing technique we demonstrated the spinal and supraspinal components of the ovarian innervation. Since increasing number of data indicate the presence of morphological and functional laterality in the control of gonadal functions, we aimed to investigate whether cerebral structures trans-synaptically involved in the innervation of the ovary exhibit asymmetry or not. In one of the studies the left or the right ovary was injected with the red fluorescent protein expressing pseudorabies virus and the number of infected "red" autofluorescent neurons from the right and the left ovary was compared.

Right occipital cortex suppresses male rat testosterone secretion by a pituitary-independent mechanism.

Objectives: In addition to being regulated by the hypothalamo-hypophyseal system, testosterone (T) secretion is influenced by a number of less understood mechanisms. The aim of the present study was to examine whether defined areas of the right cerebral cortex could modulate T production.

Methods: In adult male Wistar rats right frontal or occipital decortication, anterior or posterior callosotomy and corresponding sham-operations were performed.

Innervation and serotoninergic receptors of the testis interact with local action of interleukin-1beta on steroidogenesis.

Testosterone secretion by Leydig cells is affected by interleukin-1beta (IL-1beta). The aim of the present study was to investigate whether partial denervation of the testis or local administration of a serotonin (5-HT) receptor antagonist could alter the changes in testicular steoidogenesis induced by IL-1beta. Intratesticular administration of IL-1beta was combined with vasectomy or local injection of ketanserin (5-HT type 2 receptor antagonist) in immature hemicastrated rats and the effect of the interventions on testicular steroidogenesis was studied.

Functional significance of the innervation of the gonads.

Gonadal functions are governed by the hypothalamohypophysial system. Recent studies have demonstrated the existence of a multisynaptic neural pathway between the brain and the gonads. This review summarizes the morphological and physiological data that suggest the role of the brain-gonadal circuitry in the control of gonadal functions and discusses relevant clinical observations.

Interleukin 1-beta injected into the testis acutely stimulates and later attenuates testicular steroidogenesis of the immature rat.

The effect of intratesticular administration of interleukin-1beta (IL-1beta) on steroidogenesis was studied in immature and adult rats. In 21-d-old animals local bilateral injection or unilateral administration of 0.1 microg/testis of IL-1beta to hemicastrates resulted in a significant increase in basal testosterone secretion in vitro and serum testosterone concentration one day posttreatment.

Occasional transsynaptic viral labeling in the central nervous system from the polycystic ovary induced by estradiol valerate.

Increased density of catecholaminergic nerves in the human polycystic ovary has been observed. The aim of the present study was to investigate the distribution of transsynaptically virus-labeled neurons in the central nervous system from the rat polycystic ovary to see whether is it different or not from that of cycling control rats. To induce a polycystic ovary, a single injection of estradiol valerate was given to adult female rats and 30 days later a neurotropic virus was injected into the right ovary.

Supraspinal connections of the reproductive organs: structural and functional aspects.

Gonadal functions are governed by the hypothalamo-hypophyseal system. Other organs of the reproduction tract are under the regulatory action of gonadal steroids. In the past two decades several data have been accumulated on the involvement of fine-tuning control mechanisms which include autocrine and paracrine effects of biologically active substances produced locally and the regulatory action of nerves innervating the organs of the system.

Novel tracing paradigms--genetically engineered herpesviruses as tools for mapping functional circuits within the CNS: present status and future prospects.

The mammalian CNS is composed of an extremely complex meshwork of highly ordered interconnections among billions of neurons. To understand the diverse functions of this neuronal network we need to differentiate between functionally related and nonrelated elements. A powerful labeling method for defining intricate neural circuits is based on the utilization of neurotropic herpesviruses, including pseudorabies virus and herpes simplex virus type 1.

[Effects of extrahypothalamic brain lesions on testicular function in rats--with special emphasis on asymmetry].

Introduction: The aim of our studies was to investigate the involvement of extrahypothalamic brain structures in the control of testicular functions with special emphasis on the effect of right- and left-sided structures.

Material And Method: We performed lesion of the insular cortex, the amygdala, interrupted part of nerve fibers to and from the insular cortex, and cut the major commissural pathway of the brain the corpus callosum in adult male rats and studied the effect of the interventions on testicular steroidogenesis, serum testosterone and gonadotrop hormone concentrations.

Results: Following lesion of the insular cortex on the right side serum testosterone level and steroidogenesis of the testes decreased (in the case of the left testis the difference was significant).

Comparison of transsynaptic viral labeling of central nervous system structures from the uterine horn in virgin, pregnant, and lactating rats.

Using the transneuronal viral tracing method, the central nervous system (CNS) connections of the uterine horn were studied in virgin, pregnant, and in lactating rats. The frequency of viral labeling in the brain and the distribution of virus-infected neurons from the uterine horn were compared among groups. There was a marked difference in the frequency of viral labeling in the brain stem.

Unilateral paramedian-sagittal brain cut extending from the level of the anterior commissure to the midlevel of the third ventricle above the amygdala affects gonadal function in male rat: a lateralized effect.

The aim of the present investigations was to study involvement of fiber systems to and from the insular cortex above the amygdala in the neural control of the hypophysio-testicular axis in male rats. Animals were subjected to a unilateral paramedian-sagittal brain cut above the amygdala, extending from the level of the anterior commissure to the midlevel of the third ventricle and causing among others partial deafferentation of the insular cortex. Right-sided cut induced a significant rise in basal testosterone secretion in vitro of both testes as compared to intact or sham-operated controls without affecting serum testosterone level.

Identification of neurones of the brain and spinal cord involved in the innervation of the ductus deferens using the viral tracing method.

Using the viral transneuronal tracing technique cell groups of the spinal cord and brain transsynaptically connected with the ductus deferens were identified. Neurotropic (pseudorabies) virus was injected into the muscular coat of the ductus deferens and after survival times of 3, 4 and 5 days the spinal cord and brain were processed immunocytochemically. Virus-labelled neurones could be detected in the preganglionic sympathetic neurones and the dorsal commissural nucleus (upper lumbar segments) and in the sacral parasympathetic nucleus (L6-S1).

Supraspinal connections of the ovary: structural and functional aspects.

This review summarizes our recent studies using the viral transneuronal tracing technique to identify sites in the central nervous system (CNS) that are connected with the ovary. A neurotropic virus (pseudorabies virus) was injected into the ovary and various times after the inoculation the spinal cord and brain were examined for virus-infected neurons identified by immunocytochemistry. Such neurons could be detected in well-defined cell groups of the spinal cord (intermediolateral cell column), brain stem (vagal nuclei, area postrema, parapyramidal nucleus, caudal raphe nuclei, A1, A5, A7 noradrenergic cell groups, locus coeruleus, Barrington's nucleus, periaqueductal gray), hypothalamus (paraventricular nucleus, anterior hypothalamus, arcuate nucleus, zona incerta), and, at longer survival time, in some telencephalic structures (amygdala, bed nucleus of the stria terminalis).

The hypothalamic levels of the endocannabinoid, anandamide, peak immediately before the onset of puberty in female rats.

Several data suggest that the endogenous cannabinoid system plays a role in neuroendocrine regulation in adult individuals, although the information on its involvement in peri-pubertal processes is scarce. In the present study, we have examined the ontogeny (from postnatal day [PND] 5 up to adulthood) of hypothalamic and anterior pituitary contents of anandamide (arachidonyl-ethanolamide, AEA). We observed that the content of AEA in the hypothalamus was low at PND5, PND15 and PND25, but it markedly increased (approximately 3-fold) immediately before the puberty (on the day of 1st proestrus), to return to intermediate values immediately after the vaginal opening (day of 2nd proestrus) and, eventually, adulthood.