Thiamine-like fibers in the monkey brain: an immunocytochemical study

Mapping of folic acid in the children brainstem

Using highly specific antisera, the neuroanatomical distribution of folic acid (FA) and retinoic acid (RA) has been studied for the first time in the children brainstem. Neither immunoreactive structures containing RA nor immunoreactive fibers containing FA were found. FA-immunoreactive perikarya (fusiform, small/medium in size, one short dendrite) were only found in the pons in three regions: central gray, reticular formation, and locus coeruleus. The number of cell bodies decreased with age. In the first case studied (2 years), a moderate density of cell bodies was observed in the central gray and reticular formation, whereas a low density was found in the locus coeruleus. In the second case (6 years), a low density of these perikarya was observed in the central gray, reticular formation, and locus coeruleus. In the third case (7 years), a low density of FA-immunoreactive cell bodies was found in the central gray and reticular formation, whereas in the locus coeruleus no immunoreactive cell bodies were observed. The distribution of FA in the central nervous system of humans and monkeys is different and, in addition, in these species the vitamin was located in different parts of the nerve cells. The restricted distribution of FA suggests that the vitamin is involved in specific physiological mechanisms.

Natural plant products and extracts that reduce immunoexcitotoxicity-associated neurodegeneration and promote repair within the central nervous system

Our understanding of the pathophysiological and biochemical basis of a number of neurological disorders has increased enormously over the last three decades. Parallel with this growth of knowledge has been a clearer understanding of the mechanism by which a number of naturally occurring plant extracts, as well as whole plants, can affect these mechanisms so as to offer protection against injury and promote healing of neurological tissues. Curcumin, quercetin, green tea catechins, balcalein, and luteolin have been extensively studied, and they demonstrate important effects on cell signaling that go far beyond their antioxidant effects. Of particular interest is the effect of these compounds on immunoexcitotoxicity, which, the authors suggest, is a common mechanism in a number of neurological disorders. By suppressing or affecting microglial activation states as well as the excitotoxic cascade and inflammatory mediators, these compounds dramatically affect the pathophysiology of central nervous system disorders and promote the release and generation of neurotrophic factors essential for central nervous system healing. We discuss the various aspects of these processes and suggest future directions for study.

Direct visualization of retinoic acid in the rat hypothalamus: an immunohistochemical study

In order to increase our knowledge about the distribution of vitamins in the mammalian brain, we have developed a highly specific antiserum directed against retinoic acid with good affinity (10(-8) M), as evaluated by ELISA tests. In the rat brain, no immunoreactive fibers containing retinoic acid were detected. Cell bodies containing retinoic acid were only found in the hypothalamus. This work reports the first visualization and the morphological characteristics of cell bodies containing retinoic acid in the mammalian paraventricular hypothalamic nucleus and in the dorsal perifornical region, using an indirect immunoperoxidase technique. The restricted distribution of retinoic acid in the rat brain suggests that this vitamin could be involved in very specific physiological mechanisms.

Vitamins in the monkey brain: An immunocytochemical study

Using highly specific antisera directed against vitamins, the distribution of pyridoxal-, pyridoxine-, vitamin C- and nicotinamide-immunoreactive structures in the monkey (Macaca fascicularis) brain was studied. Neither immunoreactive structures containing pyridoxine or nicotinamide, nor immunoreactive fibers containing vitamin C were found in the monkey brain. However, this work reports the first visualization and the morphological characteristics of pyridoxal- and vitamin C-immunoreactive cell bodies in the mammalian central nervous system using an indirect immunoperoxidase technique. A high density of pyridoxal-immunoreactive cell bodies was found in the paraventricular hypothalamic nucleus and in the supraoptic nucleus and a low density of the same was observed in the periventricular hypothalamic region, whereas a moderate density of vitamin C-immunoreactive cell bodies was observed in the somatosensorial cortex (precentral gyrus). Immunoreactive fibers containing pyridoxal were only visualized in the anterior commissure. The restricted distribution of pyridoxal and vitamin C in the monkey brain suggests that both vitamins could be involved in very specific physiological mechanisms.