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D M Jacobowitz

Publications and source records attributed to D M Jacobowitz.

At least 37 records · Page 2Linked to original sources
PubMed1990

Antibody to a soluble protein purified from brain selectively labels layer V corticofugal projection neurons in rat neocortex.

An antibody to a soluble protein (protein 36) isolated and purified from rat brain labels the cell bodies and processes of pyramidal cells within layer V of the rat neocortex. We have used the fluorescent retrograde axonal tracer, Fast blue, in combination with FITC immunocytochemistry to determine the projection sites of the cortical neurons detected by this antibody. Retrogradely labeled pyramidal tract neurons and corticotectal neurons are labeled with the protein 36 antibody, but the callosally projecting neurons within layer V are not. Thus within the neocortex the antibody to protein 36 may selectively detect a particular class of neuron, the corticofugal projection neurons of layer V.

Animals↗
PubMed1990

A synthetic oligonucleotide probe encoding for atrial natriuretic peptide detects specific mRNA transcripts in rat heart but not brain using in situ hybridization histochemistry.

In situ hybridization histochemical techniques were used in an attempt to demonstrate atrial natriuretic peptide (ANP) messenger RNA (mRNA) in the rat brain. A synthetic oligonucleotide derived from previously reported ANF cDNA sequence was used as a probe. Northern blot analysis of total RNA isolated from rat heart demonstrated that the oligonucleotide recognized a single species of RNA (0.9 kb), a size consistent with previous reports. Rat heart sections revealed dense accumulations of ANF mRNA in the cardiac atria and lesser densities in the ventricles. Rat brain sections hybridized with the same oligonucleotide did not label ANF mRNA accumulations in any neuronal cell bodies. A possible explanation for this latter observation is either sparsely distributed expressing neurons or low expression and high turnover of ANF mRNA in brain.

Animals↗
PubMed1990

Localization of substance P mRNA in cholinergic cells of the rat laterodorsal tegmental nucleus: in situ hybridization histochemistry and immunocytochemistry.

1. In situ hybridization histochemical techniques in combination with immunocytochemistry and acetylcholinesterase (AChE) histochemistry were used to study the colocalization of messenger RNA (mRNA) encoding the neuropeptide substance P (SP) in cholinergic cells of the laterodorsal tegmental nucleus (LDT) of the rat pontine brain stem. 2. Alternate serial sections were hybridized with a 48-base, 35S-labeled synthetic oligonucleotide probe encoding SP using in situ hybridization histochemistry and processed either histochemically for AChE or immunocytochemically for choline acetyltransferase (ChAT). 3. In addition, serial section analysis was used to demonstrate the correlation between SP and SP mRNA in the same cells of the LDT. 4. These studies reveal that the cholinergic neurons of the LDT synthesize SP.

Acetylcholinesterase↗
PubMed1990

Detection of CCK mRNA in the motor nucleus of the rat trigeminal nerve with in situ hybridization histochemistry.

The regional distribution of dorsal pontine tegmental neurons expressing cholecystokinin (CCK) messenger RNA (mRNA) was examined using in situ hybridization histochemical techniques. A distribution of neurons containing CCK mRNA was observed in the motor nucleus of the trigeminal nerve, a region which has not been shown to contain CCK by immunocytochemical means. In addition, CCK mRNA was seen in the caudal portion of the dorsal raphe nucleus which correlates with prior immunocytochemical observations. The presence of CCK mRNA in the cholinergic motor trigeminal nucleus suggests that these cells express the CCK gene and have gone undetected in previous immunocytochemical studies. It is also suggested that CCK may have an influence on muscular contraction at sites of trigeminal nerve innervation (e.g. muscles of mastication).

Animals↗
PubMed1990

A novel autoantibody from a rabbit preimmune serum that immunostains myelinated nerves of the brain.

Preimmune serum from a rabbit was found to contain antibodies that selectively immunostained myelin in brain sections of the rat. It also reacted with oligodendroglial cells in culture as shown by double labeling with galactocerebroside. On Western blots of two-dimensional electrophoretic gels of rat cortex, this antiserum recognized a 46 kD protein with a basic pI. The presence of this protein within myelin may help identify possible cellular mechanisms of myelination and the autoimmune serum might be useful in structural studies of myelin.

Animals↗
PubMed1990

The effect of fetal mesencephalon implants on primate MPTP-induced parkinsonism. Histochemical and behavioral studies.

Parkinsonism or hemiparkinsonism was induced by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in four rhesus monkeys, which then received homologous fetal mesencephalon implants into the caudate nuclei. Cavities were prepared in the medial caudate nucleus 2 to 5 weeks before the fetal grafts were implanted. Control studies were conducted in unoperated MPTP-treated animals. Significant behavioral improvement, which occurred within weeks of implantation of fetal mesencephalon, was sustained for up to 7 months. No recovery was seen in the unoperated control animals. Histological examination revealed numerous surviving tyrosine hydroxylase (TH)-immunoreactive cell bodies. In addition to the graft, abundant TH-immunoreactive fibers were observed in the host caudate nucleus ventral to the region of the implanted and the nonimplanted cavities. Since TH-immunoreactive cell bodies of the substantia nigra compacta (A-9 cells) were destroyed by MPTP treatment and the ventral tegmental area (A-10) remained intact, it is concluded that sprouting of remaining host dopaminergic fibers occurs. These newly formed fibers appeared to emanate from the mesolimbic projection to the striatum. It is likely that the newly sprouted dopaminergic fibers account for the motor improvement elicited by precavitation and fetal mesencephalon implantation. These results suggest that the mechanism of recovery of parkinsonian primates after implantation of fetal dopaminergic tissue into the caudate nucleus is by stimulation of sprouting from host neurons. They also suggest that, with identification of the factors responsible for the formation of the new dopaminergic neuronal processes and with further development, tissue implantation may be an effective therapy for Parkinson's disease in humans.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1990

Serum autoantibodies in type 1 (insulin-dependent) diabetes mellitus: identification of reactivity against a 29 kd pancreas-specific protein.

Serum samples from patients with type 1 (insulin-dependent) diabetes mellitus and controls were incubated with two-dimensional Western immunoblots of pancreas and other tissues. Two out of 26 (8%) of the diabetics and 0 out of 45 of the controls demonstrated reactivity against four pancreas-specific proteins with identical molecular weights of 29,000 daltons and different isoelectric points ranging from pH 7.0-8.0. It is concluded that 29 Kd autoantibody reactivity is not a major marker for type 1 diabetes, but may help identify a subgroup of type 1 diabetics.

Adolescent↗
PubMed1989

A study of proteins in the auditory system of rabbits using two-dimensional gels: identification of glial fibrillary acidic protein and vitamin D-dependent calcium binding protein.

Two-dimensional gel electrophoresis and computerized optical densitometry were employed to compare the relative content of proteins across major auditory brain regions in rabbits. Areas examined included the dorsal and ventral cochlear nuclei which receive the primary afferents from the organ of Corti, the lateral superior olivary nucleus which has strong reciprocal relationships with the cochlear nucleus, and the successively more rostral projections of the auditory pathways to inferior colliculus, medial geniculate and auditory cortex. Twelve proteins demonstrated significant decreases and 5 proteins significant increases in content at successively more rostral levels of the auditory system, including 2 proteins which were highly localized to the cochlear nuclei and 2 proteins greatest in amounts in the auditory cortex. One protein which was localized to the cochlear nuclei and lateral superior olive (molecular weight (MW) = 50.3, isoelectric point (pI) = 5.7) was identified as the glial fibrillary acidic protein by reaction of specific antisera on blots. Antisera to the vitamin D-dependent calcium binding protein reacted specifically with one protein (MW = 27.2, pI = 4.8) which was greatest in amount in the lateral superior olive (LSO) versus other auditory regions examined. The significance of these findings rests in the potential for identifying specific markers for cellular elements that are important in auditory function and which might be lost as a consequence of developmental abnormalities or other traumas.

Animals↗
PubMed1989

Immunohistochemical distribution of beta-protein kinase C in rat hippocampus determined with an antibody against a synthetic peptide sequence.

An antibody directed against a synthetic peptide sequence specific for the beta-subtype of protein kinase C (PKC) was used to determine the distribution of beta-PKC in rat hippocampus by immunocytochemistry. PKC was distributed primarily in the stratum oriens and radiatum of the CA1 region. Positive staining cell bodies were only observed after colchicine treatment in pyramidal cells (CA2-CA4) and granule cells of the dentate gyrus. The discrete localization of various subtypes of PKC should provide clues to their functions.

Amino Acid Sequence↗
PubMed1989

Isolation, partial amino acid sequence, and immunohistochemical localization of a brain-specific calcium-binding protein.

A calcium-binding protein (protein 10) having a molecular mass of 29 kDa and an isoelectric point of 5.3 was purified from guinea pig brain. The amino acid sequence of fragments from proteolytic digestion of protein 10 revealed an 86% sequence identity with a calcium-binding protein (calretinin) found in chicken retina. Polyclonal antibodies against protein 10 revealed a specific distribution of this protein within sensory neurons of auditory, visual, olfactory, nociceptive, and gustatory systems as well as other discrete neuronal circuits in rat and guinea pig brain, whereas no specific label was observed in any of several peripheral tissues examined.

Amino Acid Sequence↗
PubMed1989

Rat brain protein kinase C: purification, antibody production, and quantification in discrete regions of hippocampus.

Protein kinase C (PKC), a calcium- and phospholipid-dependent kinase, is highly enriched in rat brain, where it may function in signal transduction processes. We purified rat brain PKC to homogeneity by a three-column procedure of diethylaminoethyl-cellulose, phenyl-Sepharose, and protamine-agarose with a yield of 16% and a final specific activity of 9,600 pmol of [3H]phorbol-12,13-dibutyrate bound/mg of protein. The pure protein consisted of a doublet of 80 and 78 kilodaltons. Rabbit antibodies prepared against a beta-type PKC synthetic peptide sequence (RAKIGQGTKAPEEKTANTISK) showed high specificity and sensitivity for PKC and recognized only the 78-kilodalton form of PKC. Micropunches (300 microns in diameter) of rat hippocampal subregions were solubilized in sodium dodecyl sulfate (SDS) sample buffer, electrophoresed on SDS-10% polyacrylamide gels, and transferred to nitrocellulose. PKC was visualized by 125I-protein A autoradiography and quantified by densitometry. The highest concentrations of PKC were found in the CA1 pyramidal cell layer (0.43 +/- 0.04 OD), with the lowest amounts in the CA3 and CA4 pyramidal cell layers (0.11 +/- 0.02 and 0.085 +/- 0.006 OD, respectively). These results demonstrate a simple way of preparing antibodies against domains of PKC. We also describe a procedure for quantifying the relative amounts of PKC in discrete brain regions.

Animals↗
PubMed1989

Galanin and vasopressin coexist in the rat hypothalamo-neurohypophyseal system.

Using indirect immunofluorescence methods and antisera raised against galanin (GAL) and vasopressin (VP), we have demonstrated both peptides coexisting in the very same cell bodies in the supraoptic and magnocellular paraventricular nuclei and the magnocellular accessory cells of the lateral hypothalamic area. Furthermore, dehydration and salt loading, which is known to cause release and depletion of VP and oxytocin from the neurohypophysis, also caused a marked reduction of GAL-like immunoreactivity in the posterior lobe of the pituitary but had no effect on hypothalamic GAL immunoreactivity. Systemically administered GAL caused a brief small increase in blood pressure with no effect on heart rate. A thousandfold molar concentration of GAL, compared of VP, was required to induce comparable effects on blood pressure. GAL itself had no modulatory effect on VP-induced pressor response. Systemically administered GAL resulted in mild diuresis whereas VP caused complete and sustained inhibition of diuresis. GAL had no effect on VP-induced anti-diuresis effects. The significance of the coexistence and corelease of GAL and VP remains to be elucidated.

Animals↗
PubMed1989

Quantification of proteins in discrete brain regions of androgen-insensitive testicular feminized Tfm mice.

The effect of the testicular feminization mutation (Tfm) on the concentration of specific proteins in the medial preoptic area (MPO), ventromedial hypothalamus (VMH) and parietal cortex (CX) was examined. Adult Tfm and Swiss-Webster male mice were decapitated, the brains were removed and sectioned. Proteins from the three microdissected areas were separated by two-dimensional gel electrophoresis. Gels were stained with silver and then analyzed by quantitative computerized scanning densitometry. Of the 195 proteins quantified, the Tfm mutation significantly influenced the concentration of 16 proteins measured from gels of MPO tissue, 21 from VMH gels and 11 from CX. Of these, three proteins were affected in all brain regions; and three additional proteins were shown to vary in both MPO and VMH. One protein higher in the MPO and VMH of Tfm mice was identified as the glial fibrillary acidic protein. It is suggested that the proteins influenced by the Tfm mutation are regulated by steroids, most likely androgens. Thus, these proteins may prove to be important in hormone-regulated physiological functions.

Androgen-Insensitivity Syndrome↗
PubMed1988

Central muscarinic cholinergic antagonists block wet-dog shakes produced by the TRH analog MK-771 in the rat.

Thyrotropin-releasing hormone (TRH) is known to elicit wet-dog shakes in rats through a central mechanism of action. In the present study, the ability of muscarinic cholinergic antagonists to inhibit TRH-mediated wet-dog shakes was examined. The longer-acting TRH analog, MK-771, at doses of 1.0, 1.5 and 3.0 mg/kg elicited wet-dog shakes in a dose-dependent manner. The centrally-acting muscarinic cholinergic antagonists, atropine and scopolamine, at doses of 5 and 0.8 mg/kg, respectively, significantly reduced the ability of only the highest dose of MK-771 to elicit wet-dog shakes. When the peripherally-acting antagonists, methylscopolamine and methylatropine, were examined, they were not found to significantly reduce wet-dog shakes produced by MK-771 at doses of 5 and 0.8 mg/kg, respectively. The results of this study suggest that cholinergic antagonists inhibit MK-771-induced wet-dog shakes in a noncompetitive manner and support the view that TRH-mediated wet-dog shakes are modulated by central muscarinic cholinergic systems.

Animals↗
PubMed1988

Immunocytochemical localization of peptides and other neurochemicals in the rat laterodorsal tegmental nucleus and adjacent area.

The laterodorsal tegmental nucleus (ntdl) contains a cluster of cells located just medial to the locus coeruleus in the pontine brainstem. The ntdl has been shown to project both rostrally to the forebrain and diencephalon and caudally to the spinal cord. In an effort to characterize this region neurochemically, the present study was conducted to identify a variety of neurochemicals localized within perikarya and fibers of the ntdl and surrounding nuclei. Rats were perfused with formalin, and brain sections were processed for fluorescence immunocytochemistry and acetylcholinesterase (AChE). Of the neurochemicals screened, atrial natriuretic factor (ANF), choline acetyltransferase (ChAT), cholecystokinin (CCK), calcitonin gene-related peptide (CGRP), dynorphin B (Dyn B), galanin, somatostatin, substance P, neurotensin (NT), neuropeptide Y (NPY), vasopressin, vasoactive intestinal polypeptide (VIP), serotonin (5HT), glutamic acid decarboxylase (GAD), and tyrosine hydroxylase (TH) were studied. AChE and ChAT staining revealed that the ntdl contains mostly cholinergic neurons. In addition, brightly reactive substance P and galanin and paler staining CRF, ANF, CGRP, NT, VIP, and Dyn B cell bodies were found within the ntdl. Varicose fibers in this nucleus also contained these peptides in addition to CCK, GAD, TH, 5HT, and NPY. The dorsal tegmental nucleus, dorsal raphe nucleus, locus coeruleus, and the parabrachial region contained a dense and varied assortment of peptides with distinct positions and patterns. This multiplicity of neurochemicals within this area suggests a possible influence on a variety of functions modulated by the ntdl and other closely associated tegmental nuclei.

Acetylcholinesterase↗
PubMed1988

Destruction of cells in the midportion of the locus coeruleus by a dorsal bundle lesion in neonatal rats.

Although insult of the developing noradrenergic neuronal system in the brain has been associated with redistribution of noradrenergic fiber input to various target brain regions, few studies have investigated the effects of such insults on locus coeruleus cell survival. In the present study the dorsal noradrenergic bundle was transected by means of a midbrain knife cut in rats 3 days after birth, and the effects of this lesion were determined approximately 8-10 weeks later. By means of an immunofluorescent histochemical procedure, it was shown that tyrosine hydroxylase-containing fibers and dopamine beta-hydroxylase-containing fibers were markedly reduced in number in the neocortex and hippocampus--regions anterograde to the site of axonal transection. It was further demonstrated that the number of fluorescent fibers coursing through the dorsal bundle was similarly reduced. Sprouting of noradrenergic fibers in the brainstem and cerebellum accompanied the above alterations. When locus coeruleus cell number was determined by counting Cresyl violet-stained nucleoli in serial sections it was found that dorsal bundle transection produced a loss of 17% of the cells of the coeruleus. By dividing the counts for each nucleus into fifths, it was additionally found that approximately 20-25% of those cells comprising the midportion of the nucleus, along a rostrocaudal axis, were the ones destroyed by axonal transection. These findings indicate that a neonatal lesion of the dorsal bundle produces a loss of cells in the midportion of the nucleus locus coeruleus, and that this effect is associated with noradrenergic neuronal hyperinnervation of the brainstem and cerebellum.

Animals↗
PubMed1988

Purification and immunocytochemical detection of a protein that reveals layer V pyramidal cells in the rat cortex.

Protein 36 is a soluble protein isolated and purified from a high-speed supernatant fraction from homogenates of rat brain. To identify this protein in the brain, two-dimensional gel electrophoretograms of soluble proteins were prepared. The protein was separated by ion exchange and gel filtration chromatography. The chromatographic fractions were analyzed by two-dimensional electrophoresis. Protein 36 is a homodimer with a molecular weight of 64,000 Da and monomeric weight of 37,000 Da with an isoelectric point of 6.5. A rabbit antibody was raised to this protein. Immunocytochemical studies indicate that protein 36 is localized in large pyramidal cells, dendrites and axons of layer V of the cerebral cortex. The hippocampus contained cells in the stratum radiata and processes in the stratum pyramidalis. A variety of cell types were also observed in the globus pallidus, thalamus and hypothalamus.

Amino Acids↗