Calbindin Cells Research Articles

Presence of calbindin and lack of parvalbumin in progesterone receptor-containing neurons of the monkey mediobasal hypothalamus

All of the progesterone receptor-containing cells of the monkey hypothalamus are GABAergic. The aim of this study was to further characterize these GABAergic progesterone receptor-containing neurons based on their calbindin or parvalbumin content. These calcium-binding proteins are characteristic markers of different populations of GABAergic neurons in the central nervous system. Double-immunolabeling for progesterone receptor and either calbindin or parvalbumin was performed on hypothalamic Vibratome sections of estrogen primed African green monkeys ( Cercopithecus aethiops). Progesterone receptor-containing calbindin-immunoreactive neurons were observed in the ventromedial and periventricular areas of the hypothalamus. Forty-one per cent of the progesterone receptor-containing cells in this area were calbindin immunopositive. No double-immunolabeled neurons could be detected in the infundibular (arcuate) nucleus. In tissue double-immunolabeled for progesterone receptor and parvalbumin, none of the progesterone receptor-containing neurons exhibited immunoreactivity for parvalbumin. Electron microscopic double-immunostaining for progesterone receptor and calbindin confirmed the light microscopic results. Furthermore, a large number of asymmetric synaptic contacts were observed on the calbindin-immunoreactive neurons. These observations demonstrate that progesterone receptor-containing cells in the monkey mediobasal hypothalamus consist of at least two different types of GABA neurons and indicate that progesterone receptor-containing calbindin cells may be postsynaptic targets of excitatory fibers.

Calbindin D 28k-containing nonpyramidal cells in the rat hippocampus: Their immunoreactivity for GABA and projection to the medial septum

Calbindin D 28k-containing non-pyramidal cells were found in all layers and subfields of the hippocampus, with the highest frequency in stratum radiatum of the CA1–CA3 subfields. A large number of these neurons had a vertically oriented dendritic tree, often restricted to stratum radiatum. In stratum oriens and near to the border of strata radiatum and lacunosum moleculare cells with horizontally running dendrites were also found. Multipolar cells were most common in stratum radiatum of the CA3 region. The GABAergic nature of the calbindin D 28k-containing non-pyramidal cells was studied using the “mirror” technique. Adjacent thick sections were immunostained for calbindin D 28k and GABA, and halved neurons were identified on the common surfaces. The majority of calbindin D 28k-containing non-pyramidal cells were shown to be GABAergic. The GABA-negative calbindin cells were found in relatively large numbers in stratum oriens of the CA1–CA3 region, and occasionally in strata radiatum and pyramidale of CA2, and in stratum radiatum of the CA3c region near to the border of the dentate hilus. However, even in these cells a weak immunostaining, only slightly but consistently above background level, was always observed. Earlier studies have demonstrated that the somata of GABAergic neurons with distant projections may contain a level of GABA that is below the detection threshold of immunocytochemistry. Here we provide direct evidence that the calbindin-containing non-pyramidal cells were among those projecting to the medial septum. Following horseradish peroxidase injections into the medial septum 80% of the retrogradely labelled non-pyramidal cells were found to be immunoreactive for calbindin D 28k, and 20% contained neuropeptide Y. These results suggest that the calbindin D 28k-containing and apparently GABA-immunonegative non-pyramidal cells in stratum oriens of the CAl–CA3 regions may also be GABAergic, but have a distant projection, that is, to the medial septum.

Chronic deafferentation in monkeys differentially affects nociceptive and nonnociceptive pathways distinguished by specific calcium-binding proteins and down-regulates gamma-aminobutyric acid type A receptors at thalamic levels.

Chronic deafferentation of skin and peripheral tissues is associated with plasticity of representational maps in cerebral cortex and with perturbations of sensory experience that include severe "central" pain. This study shows that in normal monkeys the nonnociceptive, lemniscal component of the somatosensory pathways at spinal, brainstem, and thalamic levels is distinguished by cells and fibers immunoreactive for the calcium-binding protein parvalbumin, whereas cells of the nociceptive component at these levels are distinguished by immunoreactivity for 28-kDa calbindin. Long-term dorsal rhizotomies in monkeys lead to transneuronal degeneration of parvalbumin cells at brainstem and thalamic sites accompanied in the thalamus by a down-regulation of gamma-aminobutyric acid type A receptors and an apparent increase in activity of calbindin cells preferentially innervated by central pain pathways. Release from inhibition and imbalance in patterns of somatosensory inputs from thalamus to cerebral cortex may constitute subcortical mechanisms for inducing changes in representational maps and perturbations of sensory perception, including central pain.

High-Resolution Light and Electron Microscopic Immunocytochemistry of Colocalized GABA and Calbindin D-28k in Somata and Double Bouquet Cell Axons of Monkey Somatosensory Cortex.

A simple method for high-resolution immunocytochemical colocalization of different antigens in semithin sections 1 - 3 microm thick was used to study the colocalization of the calcium binding protein calbindin D-28k (calbindin) with gamma-aminobutyric acid (GABA) in double bouquet cells of monkey (Macaca fuscata) somatosensory cortex. Double bouquet cells were first visualized in vibratome sections by pre-embedding immunocytochemical staining for calbindin. Sections containing calbindin-immunoreactive somata and double bouquet cell axons were then osmicated, embedded in Araldite, resectioned at 1 - 3 microm and stained for GABA by postembedding immunocytochemistry after elution of the bound anti-calbindin antibodies. Other semithin sections adjacent to those eluted and still containing calbindin immunoreactive somata and processes were resectioned at 60 - 70 nm for electron microscopy and stained immunocytochemically for GABA by the postembedding immunogold procedure. Calbindin-positive cells are most numerous in layer II and upper layer III, where they outnumber those in all other layers combined. In layers II and upper III, approximately 30% of the stained cells are pyramidal and do not colocalize GABA. Only approximately two-thirds of the calbindin-stained nonpyramidal cells in these layers colocalize GABA, but among these virtually all the calbindin-positive double bouquet cells and their axons are GABA-immunoreactive. In deeper layers all calbindin-positive cells are nonpyramidal and all colocalize GABA. At the electron microscopic level, however, significant numbers of calbindin-positive axon terminals making symmetrical synapses are not GABA-immunoreactive. These results suggest the calbindin cells of monkey somatosensory cortex are a heterogeneous population that includes GABAergic and non-GABAergic cell types.

Long-term survival of GABA-, enkephalin-, NADPH-diaphorase- and calbindin-d28k-containing neurons in fetal striatal grafts

Neurons in long-term striatal grafts were examined to determine if they retain the neurotransmitter characteristics of cells in younger grafts. In addition, calbindin-d28k, a ubiquitous marker of medium spiny neurons, was used to examine the overall frequency and ultrastructural characteristics of spiny neurons in the older grafts. Grafts from 17-days fetal striata were injected into the quinolinic acid-lesioned caudate nucleus in 5 adult rats. After 16 months, the neostriatum was processed for the localization of immunoreactive GABA, calbindin, enkephalin and NADPH-diaphorase (-d) activity. The proportions of GABA-, enkephalin- and NADPH-d-labeled neurons to total Nissl-stained neurons in the 16-month-old grafts (25 ± 6, 13 ± 4, and 3 ± 3, respectively were similar to findings in 2-month-old grafts 17. Calbindin-positive cells formed the highest proportion (36.3 ± 3) of labeled neurons in the older grafts. Nuclear and spine morphology of immunoreactive calbindin cells varied more in the grafts than in host caudate. Results show that there is long-term survival and stability of GABA, enkephalin and NADPH-d cell populations in the grafts and that some grafted spiny neurons may exhibit altered phenotype from those of host striatum.