M. Samuel Cannon

Effects of chronic methamphetamine on the nigral-striatal dopamine system in rat brain: Tyrosine hydroxylase immunochemistry and quantitative light microscopic studies

Chronic administration of methamphetamine (20 mg/kg, IP, every 12 hours for 10 days) produced a large decrease in tyrosine hydroxylase staining axons and terminal boutons in the caudate nucleus in rats when examined 60 days following the final methamphetamine injection. This effect was quantitated using the Leitz Data Acquisition and Display System (DADS) revealing that there was a 74% decrease in tyrosine hydroxylase positive processes in the caudate nucleus. Furthermore, this treatment also produced a large decrease in the number of tyrosine hydroxylase positive staining neuronal perikarya in the pars compacta of the substantia nigra. This effect was also quantitative using the Leitz-(DADS) system, revealing a decrease of 89% in tyrosine hydroxylase positive material. These data demonstrate that chronic administration of methamphetamine produces a long-term loss of tyrosine hydroxylase enzyme in both the cell bodies of the substantia nigra and the nerve terminals in the caudate nucleus. Whether this effect is due to the degeneration of the neurons or some metabolic effect remains to be determined.

Identification of dopamine-containing cell bodies in the dorsal and median raphe nuclei of the rat brain using tyrosine hydroxylase immunochemistry.

Using immunohistochemical methods with antibodies specific to tyrosine hydroxylase, we examined the distribution of dopaminergic cells in the dorsal and median raphe nucleus of the rat brain. Although dopamine-containing cell bodies were previously thought to be almost exclusively confined to the substantia nigra pars compacta, ventral tegmental area, and tuberoinfundibular system, we found numerous cell bodies which stained for tyrosine hydroxylase in the dorsal and median raphe nuclei.

Tyrosine hydroxylase immunochemistry and quantitative light microscopic studies of the mesolimbic dopamine system in rat brain: effects of chronic methamphetamine administration.

Long-term treatment of rats with methamphetamine (20 mg/kg, IP, every 12 hours for 10 days) resulted in a large decrease in tyrosine hydroxylase staining axons and terminal boutons in the nucleus accumbens and frontal cortex, as well as the ventral tegmental area of the midbrain, when examined 60 days following termination of the drug treatment regimen. Quantitative analysis showed a 71 and 78% decrease in tyrosine hydroxylase staining processes in the nucleus accumbens and frontal cortex, respectively, and a 90% decrease in tyrosine hydroxylase positive material in the ventral tegmental area. Thus, tyrosine hydroxylase enzyme in both the cell bodies of the midbrain ventral tegmental area as well as in the nerve terminals in post-synaptic target regions of the forebrain is depleted by chronic methamphetamine administration.

A rapid histological technique for localizing recording sites in single unit electrophysiological studies in vitro

Recording sites from single unit electrophysiological studies in vitro can be precisely localized by first marking the recording locus either by depositing Fast Green dye (for micropipette studies) or electrolytic lesioning (for metal electrode studies). The slices are then fixed in paraformaldehyde, placed in sucrose and attached to a coverslip by the surface tension of water. The slices are attached to a base brain in a cryostat so that the sections can be cut at the proper angle. The slices are then stained using a Nissl staining protocol. This procedure provides intact sections from small tissue slices with the recording locus clearly demarcated.

Intracellular calcium localization in stimulated and non-stimulated extraorbital lacrimal glands of rats

Acinar cells of extraorbital lacrimal glands from control, pilocarpine-treated, atropine-treated and atropine + pilocarpine-treated rats were studied using a potassium pyroantimonate technique and X-ray microanalysis for calcium localization at the ultrastructural level. This was done in order to identify intracellular compartmentalization of calcium and to elucidate any calcium translocation that might occur during the secretory process. Calcium-pyroantimonate complexes were identified in the mitochondria, plasma membrane and cytoplasmic vesicles of the untreated specimens and in the plasma membrane of atropine-treated specimens, these complexes decreased drastically in the actively-secreting cells. The function of calcium in lacrimal gland secretion and the action of pilocarpine and atropine on membrane calcium are discussed.

The myocardium and its vasculature: a histochemical comparison of the normal and chronically sympathectomized dog heart

SummaryUsing histochemical techniques, the reactivities of selected enzymes and other metabolic components were examined in the myocardium, coronary arteries, and coronary arterioles of normal, two-week-sympathectomized, and sham-operated canine hearts. There were no differences in the histochemistry of coronary arteries in any of the hearts, but important differences were noted in the myocardium and especially in the arterioles. The reactivities of the enzyme glucose-6-phosphate dehydrogenase and the nucleic acids were increased in arterioles of the sympathectomized heart, possibly indicating an increased protein synthesis. The reactivities of succinate dehydrogenase, NAD-isocitrate dehydrogenase, and cytochrome oxidase were reduced in myocardium and arterioles of sympathectomized hearts as well as in arterioles of sham-operated hearts; the changes were greater in the sympathectomized arterioles where there was also observed an increase in reactivity of lactate dehydrogenase. These findings suggest a depression in aerobic metabolic capacity and, in the case of the sympathectomized arteriole, imply a possible shift in adaptation from aerobic to anaerobic metabolism.

Cytochemistry of the Blood Basophil of Bufo marinus

The morphology and cytochemistry of the blood basophil of Bufo marinus are characterized, and compared and contrasted to the basophil from several other amphibians and with the mammalian basophil. The basophil of B. marinus contains at least one type of mucopolysaccharide and an acid mu- copolysaccharide, possibly heparin, within the cytoplasmic granules. Several amino acids, but no histidine, and no lipid, occur in B. marinus basophils. Furthermore, these basophils appear devoid of hydrolytic enzymes, excepting nonspecific esterase. They do possess numerous oxidative enzymes, however, in the intergranular cytoplasm. The basophil of B. marinus is more similar cytochemically to the mammalian basophil than to the basophil of several previously studied amphibians. Considerable information regarding the morphology and cytochemistry of the mammalian blood basophil is available (Wetzel et al., 1967; Ackerman and Clark, 1971; Komiyama and Spicer, 1974; van El- ven et al., 1977). Ackerman (1963a) pre- sents an excellent review and comparison of basophil cytochemistry in several mam- malian species, including man; he also compares and contrasts the basophil with the mast cell. In contrast, although discov- ered over a century ago, the precise func- tions of the mammalian basophil remain obscure, despite its involvement to some extent in phagocytosis, allergic reactions, and delayed hypersensitivity (Stossel, 1977). Even less is known about the am- phibian basophil. Due to the fragility of the basophil, and its infrequency (1% or less) in the peripheral blood (factors which also hindered study of this cell in mam- mals) few data regarding the amphibian basophil are available. Caxton-Martins (1978) cytochemically examined the leu- kocytes in two West African anurans, Rana temporaris and Bufo regularis, but reported his findings as granulocytes, not differ- entiating among neutrophils, eosinophils, and basophils. In the newt, Notophthalmus viridescens, Cowden et al. (1964) demon- strated the presence of mucopolysaccha- ride and tyrosine in basophilic leukocytes and tissue mast cells.

A histochemical examination of the metabolic profiles of rat ventral tegmental area and substantia nigra arterioles.

To determine the metabolic profiles of arterioles of the rat ventral tegmental area and zona compacta and zona reticulata of the substantia nigra (SN), the distribution of selected enzymes, or by-products, of key metabolic pathways were examined histologically. Arterioles of all three regions expressed the enzymes required for aerobic and anaerobic metabolism. However, the relative abundance of the enzymes and byproducts suggests a lower metabolic capacity for the SN than the ventral tegmentum, while lipid catabolism in both regions appears non-operative. Moreover, the larger ventral tegmental arterioles possess a greater potential for nucleic acid and protein synthesis. Together, these results suggest the larger ventral tegmental arterioles possess a greater capacity for proliferation and repair.

A metabolic profile of the rat caudate microvasculature: a histochemical study.

Arterioles of the rat caudate nucleus were examined histochemically to determine their metabolic profile. These microvessels appear capable of aerobic and anaerobic metabolism with a potential for nucleic acid and protein synthesis. Little intramural lipid storage occurs and any fatty acids utilized are provided via the blood supply. Likewise, glycogen is not seen in the arteriolar wall and may be rapidly turned over as a substrate for anaerobic metabolism.

A Histochemical Study of the Metabolism of Rat Renal Arteries and Arterioles

A histochemical study of the metabolism of rat renal arteries and arterioles. Rat renal arteries and arterioles were examined histochemically to determine their metabolic profiles. Succinate, malate and NAD-isocitrate dehydrogenase, cytochrome oxidase and ubiquinone were assessed to determine aerobic metabolism. Glucose-6-phosphate dehydrogenase and DPN diaphorase were evaluated to determine hexosemonophosphate-shunt activity. Anaerobic metabolism was evaluated via lactate dehydrogenase, and the substrate, glycogen. Gomoris lipase, β-hydroxybutyrate dehydrogenase and amounts of neutral fat and free fatty acids were assessed as indicators of lipid utilization. Myosin ATPase activity was evaluated as an index of ATP utilization for contraction. Deoxyribonucleic and ribonucleic acids were appraised as indicators of protein synthesis. In general, the oxidative enzymes and myosin ATPase demonstrate considerable activity in renal arteries and arterioles which suggests aerobic metabolism and ATP usage. Renal arteries and arterioles also appear capable of anaerobic metabolism as indicated by strong lactate dehydrogenase reactivity and by the presence of slight to moderate quantities of glycogen, while high levels of glucose-6-phosphate dehydrogenase and moderate amounts of deoxyribonucleic acid suggest a potential for nucleic acid and protein synthesis. In arteries and arterioles, strong reactivity for β-hydroxybutyrate dehydrogenase, minimal lipase activity, and the absence of fatty acids with substantial amounts of neutral fat, indicate limited lipid catabolism.