A projection from the entorhinal cortex to the nucleus accumbens in the rat

A study was performed in which both anterograde ([3H]leucine radioautography) and retrograde (horseradish peroxidase (HRP) histochemistry) tracing methods were employed to identify the origin of the fimbrial projection to the nucleus accumbens in the rat. The data reveal that this pathway arises predominantly from layers II--III of the anterior two-thirds of entorhinal cortex rather than from any part of hippocampal formation.

Efferent connections of the hippocampus and adjacent regions in the pigeon

In this investigation, the projections of the dorsomedial (viz. hippocampus) and adjacent dorsolateral cortical mantle (viz. parahippocampus) of the pigeon telencephalon were studied with the use of 3H-amino acid radioautography. The results indicate that the fibers which arise from these cortical areas project to the septum. The projection to this structure is topographically organized in a crude manner along the longitudinal axis of the hippocampal complex. Fibers arising from rostral levels of the dorsomedial hippocampal complex project principally to central portions of the precommissural septum and to the nucleus of the diagonal band. Cells situated in the rostral parahippocampal area project to the entire region of the commissural and precommissural septum. Fibers arising from the caudal aspect of the dorsomedial cortical mantle project ipsilaterally to the dorsolateral septum and bilaterally to central portions of the postcommissural septum. However, fibers arising from more lateral parts of cortex terminate ipsilaterally along the entire longitudinal extent of the septum. Other classical projections of the hippocampal formation in the mammal which innervate the hypothalamus and thalamus could not be identified in the present study. Thus, it appears that the projections arising from both the hippocampal formation and adjacent lateral cortices of the pigeon correspond entirely to the precommissural fornix of the mammal.

Multi-institutional outcome study on the efficacy of closed-suction drainage of the scrotum in three-piece inflatable penile prosthesis surgery

Infection is a devastating complication of penile prosthesis surgery that occurs in approximately 2-5% of all primary inflatable penile primary implants in most series. Prevention of hematoma and swelling with closed-suction drains has been shown not to increase infection rate and yield an earlier recovery time. Despite the intuitive advantages of short-term closed-suction drainage in reducing the incidence of postoperative scrotal swelling and associated adverse effects, many urologists are reluctant to drain the scrotum because of a theoretical risk of introducing an infection. In conclusion, this study was undertaken to evaluate the incidence of infection in three-piece penile prosthesis surgery with scrotal closed-suction drainage. A retrospective review of 425 consecutive primary three-piece penile prosthesis implantations was performed at three institutions in New Jersey, Ohio, and Arkansas from 1998 to 2002. Following the prosthesis insertion, 10 French Round Blake (Johnson & Johnson) or, in a few cases, 10 French Jackson Pratt, closed-suction drains were placed in each patient for less than 24 h. All subjects received standard perioperative antibiotic coverage. Average age at implant was 62 y (range 24-92 y). Operative time (incision to skin closure) was less than 60 min in the vast majority of cases. There were a total of 14 (3.3%) infections and three hematomas (0.7%) during an average 18-month follow-up period. In conclusion, this investigation revealed that closed-suction drainage of the scrotum for approximately 12-24 h following three-piece inflatable penile prosthesis surgery does not result in increased infection rate and is associated with a very low incidence of postoperative hematoma formation, swelling, and ecchymosis.

Efferent connections of the septal area in the pigeon

The efferent connections of the septum in the pigeon were studied with the use of anterograde (3H-leucine autoradiography) and retrograde (horseradish peroxidase histochemistry) transport methods. It was observed that the dorsal septum projects to the lateral hypothalamus, portions of the periventricular hypothalamus, dorsomedial thalamus and midbrain reticular formation. Fibers from the ventral half of the septum (i.e., nucleus of the diagonal band) project to medial and lateral sectors of the hypothalamus, dorsomedial thalamus, lateral habenular nucleus and midbrain tegmentum. In addition, fibers originating from this region also project to the hippocampal and parahippocampal cortices.

An analysis of the efferent connections of the septal area in the cat

The neuroanatomical organization of the efferent connections of the septal area in the cat was analyzed by the use of anterograde ([3H]leucine radioautography) and retrograde (horseradish peroxidase histochemistry) tracing techniques. The results indicate that the lateral septal nucleus projects to the nuclei of the diagonal band, preoptic area, lateral hypothalamus, and supramammillary region. The projections of the septofimbrial nucleus supply the nuclei of the diagonal band and the medial habenular nucleus. Projection targets of the vertical limb of the diagonal band are widespread and include the preoptic area, lateral hypothalamus, anterior limbic cortex, amygdala, medial habenular nucleus, interpeduncular nucleus and hippocampal formation. The projection from the vertical limb to the hippocampal formation is organized in a topographical manner in such a fashion that cells positioned near the midline project to the dorsal hippocampus and adjoining subicular cortex while fibers originating from cells situated more laterally project to more ventral parts of the hippocampal formation. In general, the projections from the horizontal limb were similar to those from the vertical limb, but several differences were noted. Fibers arising from the horizontal limb are distributed to the ventral tegmental area and interpeduncular nucleus but this region seems to lack a projection to either the habenular complex or to the ventral aspect of the hippocampal formation. Fibers arising from the bed nucleus of the anterior commissure are distributed to the preoptic region, lateral hypothalamus, supramammillary region, posterior aspect of the medial mammillary nucleus and lateral habenular nucleus.

Effects of experimental temporal lobe seizures upon hypothalamically elicited aggressive behavior in the cat

An experiment was performed in order to determine the effects of temporal lobe seizures upon hypothalamically elicited aggressive behavior in the cat. Seizures were induced by electrical stimulation of the pyriform cortex or those subnuclei of the amygdala which had previously been shown to modulate aggressive responses at subseizure current levels. The results clearly indicate that a significant modification of affective defense thresholds following seizures was a direct function of the locus of stimulation. Specifically, seizures generated from the pyriform cortex and medial aspects of the amygdala (sites associated with prior facilitation of affective defense as determined by subseizure electrical stimulation) were followed by a reduction in threshold for this response. In contrast, an elevation in affective defense thresholds occurred when seizures were generated from the central or lateral nuclei of the amygdala (sites associated with prior suppression of affective defense as determined by subseizure electrical stimulation). The primary pathway utilized in the facilitation of affective defense appears to involve the stria terminalis, its bed nucleus, and the anterior medial hypothalamus. Preliminary data suggest that seizures generated from the pyriform cortex or amygdala can also modify quiet biting attack behavior, but in a manner opposite to that demonstrated for affective defense.

Regulation of feline aggression by the bed nucleus of stria terminalis

The purpose of this experiment was to study the possible modulatory role of the bed nucleus of stria terminalis (BNST) in the regulation of affective defense and quiet biting attack reactions in the cat. The experimental paradigm employed concurrent electrical stimulation of the hypothalamic attack sites and of the BNST. The results of the present study demonstrate that concurrent electrical stimulation of the BNST can differentially modulate the two different forms of aggressive behavior by facilitating affective defense and by suppressing quiet biting attack.

Trans-abdominal monitoring of fetal arterial blood oxygenation using pulse oximetry

Pulse oximetry (oxygen saturation monitoring) has markedly improved medical care in many fields, including anesthesiology, intensive care, and newborn intensive care. In obstetrics, fetal heart rate monitoring remains the standard for intrapartum assessment of fetal well being. Fetal oxygen saturation monitoring is a new technique currently under development. It is potentially superior to electronic fetal heart rate monitoring (cardiotocography) because it allows direct assessment of both the fetal oxygen status and fetal tissue perfusion. Here we present the analysis for determining the most optimal wavelength selection for pulse oximetry. The wavelengths we chose as the most optimal are the first in the range of 670-720 nm and the second in the range of 825-925 nm. Further, we discuss the possible systematic errors during our measurements and their contribution to the obtained saturation results. We present feasibility studies for fetal pulse oximetry, monitored noninvasively through the maternal abdomen. Our preliminary experiments show that the fetal pulse can be discriminated from the maternal pulse and thus, in principle, the fetal arterial oxygen saturation can be obtained. We present the methodology for obtaining these data, and discuss the dependence of our measurements on the fetal position with respect to the optode assembly.

Loose associations and disordered speech patterns in chronic schizophrenia

The present research involves the development and utilization of a method to evaluate the free speech of chronic schizophrenic patients to measure aspects of thought disorder. Using this technique, two samples (one chronically hospitalized, the other nonhospitalized) of 15 chronic schizophrenic subjects each studied and compared. Severe types of looseness of association were not a prominent finding in the patients studied. On several of the other categories of speech patterns in investigated, multiyear hospitalized chronic schizophrenics were found to have significantly higher scores than a sample of chronic schizophrenics living in the community. This included a measure of paucity of speech, of perseveration, of repetition, and a measure of overally deviant verbalizations. The chronic schizophrenic patients generally showed high degrees of perseveration and paucity of speech, variables which may be related to impoverished thinking. The significance of these results is analyzed and discussed, with several aspects of the data suggesting that the differences may be due to severity of illness. The phenomenological scoring system developed and utilized is found to be reliable and seems to represent a useful tool for the study of many aspects of the schizophrenic patient.

Origin of the fornix system in the squirrel monkey

Wit the use of the horseradish peroxidase retrograde axonal transport technique this experiment attempted to identify the cell bodies of origin whose axons supply the septal area, mammillary bodies and the anterior thalamic complex in the squirrel monkey. It was noted that axons which innervate the anterior thalamic complex arise predominantly from the deepest cell layer of both the retrosplenial cortex and adjoining portions of subicular cortex. Hippocampal afferents to the mammillary bodies arise principally from all cell layers of the subiculum proper and to a lesser extent from the presubiculum. Afferents which innervate the septal area originate from all cell fields of the cornu Ammonis and adjacent prosubicular cortex. It was further noted that axons which are distributed to caudal levels of the septum probably arise from both the cornu Ammonis and adjacent prosubiculum, whereas axons which innervate more rostral levels of septum originate exclusively from the prosubicular cortex.

Neurotransmitters regulating defensive rage behavior in the cat

This review summarizes recent findings of our laboratory that have been directed at: (1) identifying the neural circuits underlying the expression and modulation of defensive rage behavior in the cat and the neurotransmitters associated with these pathways; and (2) determining which components of the circuitry are affected by alcohol administration and which significantly alter the rage mechanism. The experiments described herein incorporated a number of converging methods, which include brain stimulation, behavioral pharmacology, immunocytochemistry, retrograde tract tracing and receptor binding. For behavioral pharmacological studies, monopolar electrodes and cannula-electrodes were implanted into selected regions along the limbic-midbrain axis for electrical stimulation and local microinfusion of drugs. The findings demonstrated: (1) a direct pathway from the anterior medial hypothalamus to the dorsal periaqueductal gray (PAG) over which this response is mediated. This pathway utilizes excitatory amino acids that act upon NMDA receptors within the midbrain PAG; (2) that the region of the dorsal PAG, from which defensive rage could be elicited, receives other inputs from the basal amygdala that facilitate this response by acting upon NMDA receptors; (3) a pathway from the medial amygdala to the medial hypothalamus that also facilitates defensive rage and whose functions are mediated by substance P receptors within the medial hypothalamus; (4) that the PAG also receives enkephalinergic inputs from the central nucleus of amygdala, which act upon mu receptors, and which powerfully suppress defensive rage; and (5) that recent findings reveal that ethanol administration facilitates defensive rage by virtue of its interactions with the medial hypothalamus, its descending projection to the PAG, and possibly with NMDA receptors within this pathway.

Looseness of associations in acute schizophrenia

To study looseness of associations and other theoretically relevant variables of speech pathology, 51 acute psychiatric patients, including 26 schizophrenics, were studied at the acute phase of their disorder by means of a free verbalization interview. The results on these 51 patients during the acute period were: 1. There were clear differences between the schizophrenic patient group and the control patient group, the overall index of deviant verbalizations being significant at the .001 level. 2. Many types of looseness were found in non-schizophrenic patients as well as in schizophrenics. Except at the very mildest levels, however, the variants of overt looseness were strikingly more frequent in occurrence and severe in degree in the schizophrenic group (p smaller than .01). 3. Gaps in communication, vagueness of ideas and blocking, though present to some degree in our control group, were much more common in the schizophrenic sample (p smaller than .001). 4. In the control group of patients, private meanings (including neologisms), repetition and perseveration were extremely rare, and current delusional thinking virtually non-existent. Private meanings and current delusional thinking were conspicuously present in the schizophrenic sample; repetition and perseveration were present to a mild degree in this acute schizophrenic sample. 5. Schizophrenic patients tend to show more looseness of associations when faced with a request to talk about topics not related to their illness.

Plasma catecholamine and cardiovascular responses following hypothalamic stimulation in the awake cat

Ninety-three hypothalamic sites were electrically stimulated, using constant parameters, in awake, restrained cats to determine those regions which maximally activated the sympatho-adrenal (SA) and cardiovascular (CV) systems. Plasma catecholamine levels were measured over time following hypothalamic stimulation; levels of norepinephrine (NE) and epinephrine (E) served as indices of adrenergic neural and adrenal medullary activities, respectively. CV parameters of heart rate (HR) and mean intra-arterial blood pressure (MAP) were continuously monitored. The greatest elevation in plasma catecholamines was elicited by stimulation of sites in the perifornical area, ventromedial nucleus, and medial forebrain bundle. Several sites were identified which preferentially elevated one of the sympatho-adrenal neurotransmitters. A differential increase in plasma E was most frequently obtained from sites around the border of the ventromedial nucleus and in the medial forebrain bundle. Differential elevation of plasma NE was observed following stimulation of sites in the anterior commissure, central preoptic area, and dorsal perifornical region posterior to the ventromedial nucleus. Sites which activated the CV and SA systems were not always coincident; those sites which activated the CV system alone tended to be located in the lateral hypothalamus.