Research reportCalbindin D-28k positive projection neurones and calretinin positive interneurones of the rat globus pallidus
Introduction
Until recently, the globus pallidus (GP: equivalent to the external segment of the primate globus pallidus) was viewed as a simple structure composed of a homogenous population of neurones which act as relays between the striatum and the subthalamic nucleus. With advances in techniques, this view has recently been challenged and the GP is now considered a heterogeneous structure which has a wide range of connections throughout the basal ganglia [41] including the internal segment of the globus pallidus [21] and the substantia nigra pars reticulata [40], the striatum [42], the reticular thalamic nucleus [39] and the pedunculopontine region [28].
Morphological studies using the Golgi technique [25], [17] and intracellular staining combined with electrophysiology [33], [24] have revealed multiple GP neuronal subtypes. In vivo, multiple subtypes of rat GP neurone have been identified on the basis of firing pattern and waveform [23], while sharp microelectrode studies in vitro have indicated that the guinea pig GP contains three neuronal subtypes [29], [30]. Our own patch clamp studies in slices of rat GP have identified two major populations of GP neurones which can be distinguished on the basis of membrane properties and morphology [45].
Differences in neuronal electrophysiological characteristics are often accompanied by differential neurochemical expression. At the macroscopic level, the GP exhibits a complementary pattern of parvalbumin (PV) and calbindin (CB) neuropil expression [10], [36]. However, to date, only PV positive cell bodies have been observed in the rat GP [15], [36] although CB positive [10], [32] and calretinin (CR) positive neurones [13], [32] have been observed in the GPe of the primate.
The aim of the current study was to determine whether pallidal neurones could be identified on the basis of somal PV, CB or CR expression and whether there is evidence for the co-localisation CaBPs as in other areas of the basal ganglia such as substantia nigra pars compacta [38] and subthalamic nucleus [1]. Immunohistochemistry for CaBPs was coupled with retrograde tract tracing to determine whether their differential expression could be used as a marker neuronal phenotype in the GP.
Section snippets
Subjects
Male Sprague–Dawley rats (110–140 g) were used throughout the study in order to permit comparisons with the results of in vitro electrophysiological studies being conducted in the laboratory [45]. The animals were group housed on a 12 h-light/dark cycle and given free access to food and water. All procedures were conducted in accordance with the Animals (Scientific Procedures) Act, 1986, UK.
Retrograde neuroanatomical labelling of globus pallidus neurones
A colloidal gold tracer was stereotaxically injected into 18 animals, which had been anaesthetised with
Distribution of calcium binding protein immunoreactivity
At a macroscopic level, CB positive neuropil staining was highest in the medial parts of the GP, although a thin band of staining was also seen adjacent to the striatal border. CB positive cell bodies (8.35±0.74 cell bodies per GP section; mean±S.E.M.) were observed throughout the GP (Fig. 1A). Cell bodies were multipolar, bipolar or fusiform in shape (mean dimensions 19.92±0.55×11.8±0.24 μm) with smooth or moderately varicose processes (Fig. 2A). Many of the bipolar neurones lay parallel to
Discussion
The results demonstrate that both CB and CR immunopositive neurones were distributed throughout the GP. In keeping with previous studies, many PV positive cell bodies were observed the density of which was greatest in the lateral parts of the structure [4], [15], [22], [36]. Sequential double immunohistochemical processing suggests that these CaBPs be uniquely expressed with no more than one CaBP being localised in a single cell. Furthermore, combined immunohistochemistry and retrograde
Acknowledgements
The authors wish to thank Dr I.J. Mitchell for use of the photomicroscope system and for invaluable assistance in criticising the manuscript. This work was supported by the Wellcome Trust, UK (Grant No. 050196/Z/97/Z) and a Research Project Grant from the Faculty of Medicine and Dentistry, University of Birmingham.
References (49)
- et al.
Localisation of calcium-binding proteins and GABA transporter (GAT-1) messenger RNA in the human subthalamic nucleus
Neuroscience
(1999) - et al.
Calcium-binding proteins in the nervous system
Trends Neurosci.
(1992) Calbindin D28k and parvalbumin in the rat nervous system
Neuroscience
(1990)- et al.
Monoclonal antibodies directed against the calcium binding protein parvalbumin
Cell Calcium
(1988) - et al.
Monoclonal antibodies directed against the calcium-binding protein calbindin D-28k
Cell Calcium
(1990) - et al.
Sparing of striatal neurones coexpressing calretinin and substance P (NK1) receptors in Huntington’s disease
Brain Res.
(1996) Calcium-mediated neurotoxicity: relationship to specific channel types and role in ischemic damage
Trends Neurosci.
(1988)- et al.
A subset of striatopallidal neurones are Fos-immunopositive following acute monoamine depletion in the rat
Neurosci. Lett.
(1995) - et al.
Striatal interneurones: Chemical, physiological and morphological characterisation
Trends Neurosci.
(1995) - et al.
Fast-spiking cells in rat hippocampus (CA1 region) contain the calcium-binding protein parvalbumin
Brain Res.
(1987)
Regulation of neuronal function by calcium
Trends Neurosci.
Evidence for a projection from the globus pallidus to the entopeduncular nucleus in the rat
Neurosci. Lett.
Parvalbumin immunopositive neurones in rat globus pallidus — a light and electron microscopic study
Brain Res.
Intracellular study of rat globus pallidus neurones: membrane properties and responses to neostriatal, subthalamic and nigral stimulation
Brain Res.
The morphology of globus pallidus projection neurones in the rat: an intracellular staining study
Brain Res.
Use of peroxidase substrate vector VIP® for multiple staining in light microscopy
J. Neurosci. Methods
Glutamate-induced apoptosis results in a loss of striatal neurones in the parkinsonian rat
Neuroscience
Separate neuronal populations of the rat globus pallidus projecting to the subthalamic nucleus, auditory cortex and pedunculopontine tegmental area
Neuroscience
Calcium-binding proteins in primate basal ganglia
Neurosci. Res.
The EF-hand family of calcium-modulated proteins
Trends Neurosci.
Calretinin in rat brain; an immunohistochemical study
Neuroscience
Calretinin and calbindin D-28k in rat brain — patterns of partial colocalisation
Neuroscience
Neurones of the substantia nigra pars reticulata receive a dense GABA-containing input from the globus pallidus in the rat
Brain Res.
Demonstration of a pallidostriatal pathway by retrograde transport of HRP-labelled lectin
Brain Res.
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2010, Handbook of Behavioral NeuroscienceCitation Excerpt :In the rat GPe, recent evidence indicates that the GABAergic projection neurons co-express either calbindin or parvalbumin or neither of these calcium-binding proteins (Cooper and Stanford, 2002). Since calcium-binding proteins are known to have unique buffering kinetics, the differential expression of these proteins may underlie the electrophysiological heterogeneity observed in the rat GPe (Cooper and Stanford, 2002). In living cells, calbindin is considered to be a fast calcium buffer, whereas parvalbumin is a slow-onset calcium buffer (Schwaller et al., 2002).