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M V Sofroniew

Publications and source records attributed to M V Sofroniew.

At least 91 records · Page 5Linked to original sources
PubMed1983

Retrograde changes in cholinergic neurons in the basal forebrain of the rat following cortical damage.

The effects of unilateral cortical damage on immunohistochemically identified cholinergic neurons of the basal nucleus have been examined in the rat. In the first 2 weeks after operation, the cells were swollen and their nuclei became eccentric, these changes being closely similar to those seen in the cholinergic oculomotor nuclei of the same animals following removal of the extraocular muscles. During the third week these acute changes were replaced by shrinkage of the cholinergic cell bodies and their dendrites. At longer survival times the appearance of the neurons did not alter, and all the cholinergic cells persisted in their shrunken form after 120 days, the longest survival time examined.

Acetylcholine↗
PubMed1983

Persistence of cholinergic neurons in the basal nucleus in a brain with senile dementia of the Alzheimer's type demonstrated by immunohistochemical staining for choline acetyltransferase.

Immunohistochemically identified cholinergic neurons in the basal nucleus of Meynert in a brain with SDAT have been compared with those in two age- and sex-matched normal brains. The numbers of such cells at carefully matched levels are not significantly lower, but the cells in SDAT are substantially smaller than in the normal basal nucleus. The persistence of shrunken cholinergic neurons in the basal nucleus in the diseased brain is similar to that seen in an experimental study of retrograde cellular degeneration in the nucleus following damage of the cortex.

Acetylcholinesterase↗
PubMed1983

Direct reciprocal connections between the bed nucleus of the stria terminalis and dorsomedial medulla oblongata: evidence from immunohistochemical detection of tracer proteins.

Connections between the bed nucleus of the stria terminalis and the dorsomedial medulla oblongata have been examined by immunohistochemical detection of the tracer proteins horseradish peroxidase (HRP) or wheat germ agglutinin (WGA). Two sets of four rats received 0.2 or 0.4 microliter of either tracer injected into the dorsomedial medulla oblongata, were fixed by perfusion 48 hours later, and were processed for immunohistochemical detection of the tracers. Rats receiving HRP showed only a few single neurons retrogradely labelled in the ipsilateral bed nucleus, and some anterogradely labelled fibers. Rats receiving WGA showed a large number of retrogradely labelled neurons in the ipsilateral bed nucleus. Labelled neurons were most concentrated in a group in the central, dorsal, and lateral aspects of the nucleus at the level of the anterior commissure and just caudal to this. Just ventral to this group was a dense cluster of anterogradely labelled fibers. The retrogradely labelled neurons ranged from 12 to 20 microns in size and were multipolar. These findings indicate that there are direct reciprocal connections between the bed nucleus of the stria terminalis and the autonomic centers of the dorsomedial medulla oblongata and strengthen the concept that this nucleus is involved in forebrain integration of autonomic functions.

Afferent Pathways↗
PubMed1983

Naloxone reversible inhibition of reticular neurones in the rat caudal medulla produced by electrical stimulation of the periaqueductal grey matter.

Chronic dorsal periaqueductal grey matter electrodes were implanted into adult rats under pentobarbitone anaesthesia. Stimulating these electrodes (25-300 microA) produced behavioural analgesia in 23 of 44 rats tested. In rats given the opiate antagonist naloxone attenuation of this analgesia was seen. In 14 rats displaying behavioural analgesia to periaqueductal grey matter stimulation acute electrophysiological experiments were performed under urethane anaesthesia. Microelectrode recordings were made from neurones, excited by noxious heat or pinch applied to the limbs and tail, and located in the reticular formation of the caudal medulla. Stimulation of the periaqueductal grey matter at an intensity sufficient to produce analgesia in the conscious animal produced direct inhibition of the firing of 62% of neurones tested, excited 23%, had no effect on 14% and attenuated the nociceptive responses of 66%. The inhibitions were characteristically long. Local application of naloxone by microiontophoresis attenuated these long inhibitions in 11 out of 16 neurons tested. Immunohistochemical localization of beta-endorphin containing structures in the vicinity of stimulating and recording sites suggested that the naloxone sensitive inhibition of nociceptive neuronal responses in caudal medulla reticular formation may be due to activation of beta-endorphin fibres descending through the periaqueductal area to the caudal medulla.

Action Potentials↗
PubMed1983

Immunocytochemistry and neurobiology.

Immunocytochemistry enables the localization of transmitter-related antigens in tissue sections at either the light microscopic or the electron microscopic level. In the case of neuropeptides and certain transmitters (e.g. serotonin) it has been possible to produce antibodies directed against the putative transmitter itself. In other cases it has not been possible to produce useful antibodies against transmitters but antibodies have been raised against enzymes involved in transmitter metabolism (e.g. tyrosine hydroxylase, glutamic acid decarboxylase) and these antibodies are suitable markers for transmitter systems. Successful immunostaining with an antibody depends on a number of factors, two of the most important being the fixation of the antigen in the tissue and the visualization of the primary antibody once it has bound to the antigen. Techniques available for the visualization of bound primary antibody include the indirect-labelled immunofluorescence procedure and the unlabelled peroxidase-antiperoxidase (PAP) procedure. Direct-labelled immunocytochemistry is not now widely used but is likely to become increasingly important with the introduction of monoclonal antibodies and the development of techniques for the simultaneous localization of multiple antigens. Monoclonal antibody procedures also allow the production of antibodies against antigens which are difficult to purify such as certain transmitter markers (e.g. choline acetyltransferase) and constituents of neuronal membranes. Immunocytochemistry allows the production of detailed maps of the distribution of putative transmitters in the nervous system and in combination with tract tracing procedures is being used increasingly to identify transmitters in neuronal circuits. It has also been important in establishing the transmitter status of various neuroactive compounds in single neurones. Immunocytochemistry can be carried out on post-mortem samples and is providing information on transmitter distribution in normal and abnormal human brain.

Antibodies, Monoclonal↗
PubMed1983

Identification of central cholinergic neurons containing both choline acetyltransferase and acetylcholinesterase and of central neurons containing only acetylcholinesterase.

Neurons in the rat central nervous system (CNS) were examined for their content of both the acetylcholine-synthesizing enzyme, choline acetyltransferase (ChAT; acetyl-CoA, choline O-acetyl-transferase, EC 2.3.16), and the transmitter-degrading enzyme, acetylcholinesterase (AChE). ChAT was localized immunohistochemically and AChE was localized histochemically in normal, colchicine-treated, or diisopropylfluorophosphate (DFP)-treated rats, either in neighboring sections by standard procedures or simultaneously in the same sections by immunofluorescence for ChAT, followed by photography, followed by histochemistry for AChE, followed by brightfield rephotography of the same neurons. This combination of fluorescence and brightfield procedures allows both to be carried out at maximum intensity without fear of interference and enables the unambiguous visualization of all neurons that might be expected with either procedure. Based on previous examination of singly stained neighboring sections, five CNS areas were examined in detail in DFP-treated rats using the simultaneous procedure for localizing both ChAT and AChE in the same neurons in the same sections. Several hundred neurons were thus examined in each area. These areas were the caudate putamen, nucleus basalis of Meynert, medial septum, nucleus of the diagonal band of Broca (vertical and horizontal limbs), and zona incerta. In the caudate putamen and nucleus basalis magnocellularis of Meynert, all ChAT-positive neurons contained AChE and vice versa. In the medial septum and nucleus of the diagonal band of Broca, all ChAT-positive neurons contained AChE, but these neurons containing both ChAT and AChE were intermingled with neurons positive only for AChE.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1982

Long-term storage and regular repeated use of diluted antisera in glass staining jars for increased sensitivity, reproducibility, and convenience of single- and two-color light microscopic immunocytochemistry.

A procedure is described for the dilution and storage of antisera in glass staining jars into which whole slides are immersed for incubation during light microscopic neuropeptide immunocytochemistry. Diluted antisera, stored at 4 degrees C and continuously reused, were found to be stable for long periods of time (to date over 3 years), and consistently yielded high quality staining in both single- and two-color immunoperoxidase staining. We found this procedure to be more convenient than conventional incubation procedures, allowing the more rapid processing of large numbers of slides and reducing the loss of slides due to technical errors. The consistency and reproducibility of day to day staining were also improved. The immersion of whole slides into the antisera permitted the use of long incubation times (up to 7 days) without the sections drying out, which in many cases substantially enhanced the sensitivity of the staining obtained. A procedure for two-color immunoperoxidase staining is described using diaminobenzidine for a brown color and alpha-naphthol/pyronin for a red/purple color. We found the alpha-naphthol/pyronin reaction superior to the more commonly used 4-chlornaphthol reaction as a second color. The two-color staining was found useful not only for demonstrating nerve cell bodies stained different colors, but also for staining nerve terminals one color that are around and contacting nerve cell bodies stained another color.

Adrenocorticotropic Hormone↗
PubMed1982

Use of serial 1-2 micrometer paraffin sections in neuropeptide immunocytochemistry for sequential analysis of different substances contained within the same neurons.

The preparation of serial 1.0, 1.5, or 2.0 micrometer paraffin sections is described. The sections are cut from paraffin blocks with surface areas of up to 5 mm x 10 mm, using glass knives and a Jung Autocut microtome. Large numbers of serial sections can easily be prepared and stained by immunohistochemistry for sequential analysis. These sections are useful for demonstrating several different substances contained within the same neurons or for detailed topographical comparison of neurons that contain different substances within the same nucleus.

Animals↗
PubMed1981

Immunohistochemistry of vasopressin, oxytocin and neurophysin in the hypothalamus and extrahypothalamic regions of the human and primate brain.

Vasopressin, oxytocin and neurophysin were localized in the brains and spinal cords of four primates (tree shrew, squirrel monkey, rhesus monkey and human) using antisera to these peptides and the unlabelled antibody-enzyme peroxidase antiperoxidase method. Magnocellular neurons in the hypothalamus stained positively for vasopressin, oxytocin or neurophysin. Parvocellular neurons of the suprachiasmatic nucleus (SCN) stained positively for vasopressin and neurophysin but not for oxytocin, in all four species. Magnocellular oxytocin, vasopressin and neurophysin neurons project to permeable capillaries in the neurohypophysis, as well as to various extrahypothalamic neural target areas including the central amygdala, nucleus of the solitary tract, dorsal motor nucleus of the vagus, lateral reticular nucleus, dorsal horn, central grey and intermediolateral nucleus of the spinal cord. In target areas, terminals contact somata and dendrites. Parvocellular vasopressin and neurophysin neurons of the SCN do not project to the neurohypophysis, and project only to neural target areas, including the lateral septum, mediodorsal thalamus, lateral habenula, mesencephalic central grey, medial amygdala and ventral hippocampus. (Due to the relatively poor tissue preservation in human autopsy specimens not all projections found in the other primates could be confirmed in humans.) These findings confirm and correlate well with previous descriptions made in rodents, and indicate that vasopressin, oxytocin and neurophysin projections to neural targets are present in primates. Peptides released from these projections probably do not enter the bloodstream, but are rather involved in neural mechanisms.

Animals↗
PubMed1981

Relation of neuropeptides to mammalian circumventricular organs.

In summary, highly vascularized CVOs of the mammalian brain are the site of increased vascular permeability for peptides and other molecules which generally do not cross the blood-brain barrier. In the CVOs the blood-brain barrier is shifted from the level of the capillaries to the tight junctions of the oligociliated ependymal cells. The neurohypophysis is the well known target of various peptidergic neuroendocrine neurons. In the neural lobe, peptide hormones from magnocellular neurons are stored and released into the general circulation in the median eminence, releasing and inhibiting hormones enter the hypothalamo-adenohypophyseal portal circulation. The OVLT appears to be an additional vascular outlet for LHRH and somatostatin. In the pineal, no pinealocytes stain positively for arginine-vasotocin; however, occasionally a single neurophysin (vasopressin or oxytocin) fiber has been observed. In the subfornical organ and area postrema which do not appear to have a primary neuroendocrine function, hemo-neural interactions may be important for effects of circulating peptides and other molecules on specific receptors. In the subcommissural organ, which does not have a special vascular permeability, ependymal cells secrete Reissner's fiber, a mucopolysaccharide, whose function in unclear.

Animals↗
PubMed1980

Hypothalamic neurons projecting to the rat caudal medulla oblongata, examined by immunoperoxidase staining of retrogradely transported horseradish peroxidase.

Horseradish peroxidase (HRP), injected into the rat caudal medulla oblongata, was detected by immunoperoxidase staining in 120 microns frozen sections, allowing examination of both the distribution and morphology of transporting neurons. In the hypothalamus, several groups of HRP-labeled neurons could be distinguished on the basis of location of the neurons, neural cell size and morphology of the neural processes. Most HRP-labeled neurons were found in the posterior half of the hypothalamus, although scattered single neurons were present as far rostral as the anterior hypothalamus and preoptic area. Prominent groups of HRP-labeled neurons were found in the paraventricular, dorsomedial and arcuate nuclei, near the fornix at two separate levels, and in the lateral posterior hypothalamus. Based on comparison with peptide immunohistochemistry it seems likely that many magnocellular oxytocin, vasopressin and neurophysin neurons in the paraventricular nucleus, and a few ACTH/beta-endorphin neurons in the arcuate nucleus may project to the caudal medulla oblongata.

Animals↗
PubMed1980

Identification of parvocellular vasopressin and neurophysin neurons in the suprachiasmatic nucleus of a variety of mammals including primates.

The presence of parvocellular vasopressin- and neurophysin-containing neurons in the suprachiasmatic nucleus (SCN) was investigated in 13 mammalian species representing six mammalian orders (marsupials, rodents, lagomorphs, artiodactyls, carnivores, and primates), using specific antisera to vasopressin and neurophysin in the unlabelled antibody=enzyme immunoperoxidase method. In all mammals examined, including man, parvocellular vasopressin and neurophysin neurons were found in the SCN. Only a portion of SCN neurons contain vasopressin and neurophysin, the number varying with species. Cell counts comparing the number of immunoreactive to Nissl-stained neurons showed averages of 17% immunopositive neurons in the rat SCN, and 31% in the human SCN. No oxytocin-containing SCN neurons were observed. These findings suggest that parvocellular vasopressin and neurophysin neurons are widely represented in mammals.

Animals↗