Co-localization of glutamate, choline acetyltransferase and glycine in the mammalian vestibular ganglion and periphery

Nuclear-cytoplasmic localization of acetyl coenzyme a synthetase-1 in the rat brain

Acetyl coenzyme A synthetase-1 (AceCS1) catalyzes the synthesis of acetyl coenzyme A from acetate and coenzyme A and is thought to play diverse roles ranging from fatty acid synthesis to gene regulation. By using an affinity-purified antibody generated against an 18-mer peptide sequence of AceCS1 and a polyclonal antibody directed against recombinant AceCS1 protein, we examined the expression of AceCS1 in the rat brain. AceCS1 immunoreactivity in the adult rat brain was present predominantly in cell nuclei, with only light to moderate cytoplasmic staining in some neurons, axons, and oligodendrocytes. Some nonneuronal cell nuclei were very strongly immunoreactive, including those of some oligodendrocytes, whereas neuronal nuclei ranged from unstained to moderately stained. Both antibodies stained some neuronal cell bodies and axons, especially in the hindbrain. AceCS1 immunoreactivity was stronger and more widespread in the brains of 18-day-old rats than in adults, with increased expression in oligodendrocytes and neurons, including cortical pyramidal cells. Expression of AceCS1 was substantially up-regulated in neurons throughout the brain after controlled cortical impact injury. The strong AceCS1 expression observed in the nuclei of CNS cells during brain development and after injury is consistent with a role in nuclear histone acetylation and therefore the regulation of chromatin structure and gene expression. The cytoplasmic staining observed in some oligodendrocytes, especially during postnatal brain development, suggests an additional role in CNS lipid synthesis and myelination. Neuronal and axonal localization implicates AceCS1 in cytoplasmic acetylation reactions in some neurons.

Histochemical and immunocytochemical investigations of the marginal nuclei in the spinal cord of pigeons (Columba livia)

In birds there are segmentally organized marginal nuclei at the lateral or ventrolateral border of the spinal cord. In most regions of the spinal cord these nuclei are within the outline of the cord. However, in the lumbosacral region they form accessory lobes protruding into the vertebral canal. Histochemical and immunocytochemical investigations were performed to study the neurochemical features of the marginal nuclei of the pigeon. Despite histological differences (only accessory lobe neurons are embedded in glia-derived glycogen cells), there was no difference in the chemical neuroanatomy of the two types of marginal nuclei. These nuclei contained cholinergic neurons and there was also evidence for a cholinergic innervation. NADPH-diaphorase activity, which is considered to indicate nitric oxide synthesis, was faint in marginal neurons. No serotonin immunoreactivity was found. However, all neurons showed immunoreactivity to glutamate and glycine, and some were immunoreactive to gamma-aminobutyric acid (GABA). A GABAergic innervation of non-GABAergic neurons could also be demonstrated. The lack of difference in the chemical neuroanatomical features between cervical marginal nuclei and lumbosacral accessory lobes suggests a similar origin of all marginal neurons. A comparison with the chemical neuroanatomy of marginal neurons in other vertebrates shows both similarities and differences.