A comparative study of the mammalian amygdala: a Golgi study of the basolateral amygdala

The lateral (LA), basolateral (BL) and basomedial (BM) amygdaloid nuclei were compared in the guinea pig (Cavia porcellus), rabbit (Oryctolagus cuniculus) fox (Vulpes vulpes) and pig (Sus scrofa) by using the Golgi techniques. The interspecific comparisons of the individual basolateral nuclei have shown that the neuronal structure in each of them is extremely stable and remains almost unchanged in the series of animals studied. The only difference is the size of the basolateral neurons, which increases with the increasing size of the brain. Moreover, the intraspecific comparisons revealed that in all the animals studied LA, BL and BM form a fairly homogenous mass of cells in which similar cell types are present. The most numerous neurons in all basolateral nuclei are the spiny cells that often show a pyramidal or semi-pyramidal appearance (the Type I cells). Many of these have conical cell bodies and easily recognisable "apical" and "basal" dendrites. The Type II neurons are the most common variety of non-pyramidal cell and have round cell bodies and smooth or sparsely spined dendrites. The axons of these cells often form a dense terminal field that remains in the vicinity of the parent soma. The Type III cells, which are only occasionally seen, are small spine-sparse neurogliaform neurons with a few extremely delicate beaded dendrites and a poorly branching local axon. These neurons were only located in LA and BL

The neuronal structure of the globus pallidus in the rabbit - Nissl and Golgi studies

The studies were carried out on the telencephalons of 12 adult rabbits. Two types of neurons were distinguished: 1. Large neurons (perikarya 18–40 μm), which have from 2 to 6 thick, long primary dendrites. Their perikarya have a polygonal, triangular and fusiform shape. The large neurons in the centre of GP have radiated dendritic trees, whereas the dendritic field of the cells along the borders of GP has an elongated shape. The dendritic arbour is not homogeneous. The dendrites may be covered with spindle-shaped dendritic swellings, bead-like processes, not numerous spines or they may be smooth as well. The dendritic branches form thin, beaded dendritic processes, that arise from any part of the dendritic tree, as well as “complex terminal endings”, which have various types of appendages on their terminal portions. An axon emerges from a thick conical elongation either from the cell body or one of the dendritic trunks. These neurons are the most numerous in the investigated material. 2. Small nerve cells have been infrequent in our material. Their cell bodies are rounded or polygonal. From the perikarya there arise 2–4 thin dendritic trunks, which may have irregular swellings and few spines. The dendrites spread out in all directions, making the dendritic field round or oval in shape. Generally most axons of the small cells have not been impregnated. However, a few of them have a thin axon with a conical elongation, which emerges from the cell body and bifurcates into beaded processes

The types of neurones in the neostriatum of the guinea pig (Cavia porcellus): Golgi and Klüver-Barrera studies

The Golgi technique stain was used to reveal the cellular structure of the neostriatum (nucleus caudatus and putamen) in the guinea pig. The computerised reconstructions were made from Golgi impregnated neurones. On the basis of various criteria, 4 types of neurones were distinguished in the guinea pig neostriatum: 1. The rounded neurones (most numerous) with 5–8 thin dendritic trunks; 2. The triangular nerve cells with 3 thick dendritic trunks; 3. Two types of multipolar neurones differing in dendritic arborisation pattern with 4–6 and 7–9 primary dendrites, respectively. 4. The pear-shaped cells, which divide into two distinctly different subpopulations

A morphometric study of the amygdala in the common shrew

The characteristic features of the common shrew amygdala (CA), as shown by volumetric comparisons of the individual nuclei, are the poor development of the lateral (LA) and basomedial (BM) nuclei as well as the particularly strong formation of the basolateral (BL) and lateral olfactory tract (NLOT) nuclei. The central (CE), cortical (CO) and medial (ME) nuclei are also well organised in this species. All these features are even more distinctly visible when the total number of neurons in the nuclei referred to are compared. A comparison of the densities of neurons in the individual nuclei with the mean numerical density of cells in the CA indicates that there are the 3 different regions within the common shrew&#8217;s CA. The densities of neurons in the LA, BL, and BM are significantly lower than the mean density of cells in the CA (p < 0.05). In the CE this value does not differ from the mean (p > 0.05). In the CO, ME and NLOT the density values are significantly higher than the mean (p < 0.05). Furthermore, a similar division of the shrew&#8217;s CA can, to some extent, be performed using the size parameters of the amygdaloid neurons as a marker. Interestingly, the large neurons populate less densely organised CA areas like the LA, BL and BM, whereas the small cells populate the ME and NLOT, where the neurons are densely arranged. The CE and CO occupy intermediate positions, with the neurons similar in size to the mean for the shrew&#8217;s CA

The neuronal structure of the substantia nigra in the guinea pig: Nissl and Golgi study

The studies were carried out on the mesencephalons of adult guinea pigs. The preparations were made by means of the Golgi technique, as well as the Nissl and Klüver-Barrera methods. Four types of neurons were distinguished in the substantia nigra (SN) of the guinea pig: 1. Bipolar neurons of two kinds: the neurons of the first kind have elongated, fusiform perikarya (25-40 &micro;m), whereas the cells of the second kind have rounded and oval perikarya (15-22 &micro;m). These neurons possess two dendritic trunks which arise from the opposite poles of the cell body and run for a relatively long distance. The bipolar neurons are the most numerous in the pars compacta of SN. 2. Triangular neurons with three primary dendrites arising conically from a perikaryon (20-35 &micro;m). They are the most often observed type of neurons in the pars reticulata of SN. 3. Multipolar neurons with quadrangular or oval perikarya (22-35 &micro;m) and 4-5 dendritic trunks which spread out in all directions. 4. Pear-shaped neurons (perikarya 15-25 &micro;m), which have one or two primary dendritic trunks arising from one pole of the cell body. In all the types of neurons an axon originates either from the dendritic trunk or from the soma and is observed only in its initial segment

The neuronal structure of the inferior colliculus in the bank vole (Clethrionomys glareolus) - Golgi and Nissl studies

The inferior colliculus (IC) of the bank vole is made up of 3 nuclei: the external and pericentral nucleus, which are located on the outer border of the IC, and the central nucleus, which is the largest part of IC and shows a laminated structure. On the basis of various morphological criteria 5 types of neurons have been distinguished in the bank vole IC: 1. The rounded cells (perikarya 10-15 &micro;m) with 2&#8211;4 primary dendritic trunks. The dendritic tree has a spindle-like shape. The axon emerges from the soma or from the proximal portion of a dendrite. 2. The fusiform neurons (17-20 &micro;m) with 2 primary dendrites arising from both poles of the perikaryon. The dendritic tree has the same shape as the previous type. The axon originates from the proximal dendritic trunk. The rounded and fusiform cells constitute the main neuronal type. 3. The pear-shaped neurons (10&#8211;13 &micro;m) with 2 main stems or rarely 1. The axon emerges from the perikaryon or seldom from the dendritic trunk. 4. The multipolar cells (18&#8211;23 &micro;m), which have from 4 to 6 primary dendrites radiating in all directions. The dendritic tree has a spherical shape. The axon emerges either from the proximal stem or directly from the soma. 5. The triangular neurons (15&#8211;18 &micro;m) with 3 primary dendritic trunks. The axon originates from the perikaryon. The triangular cells are the least numerous. All types of neurons in the bank vole IC bear spines and protrusions

Types of neurons of the subthalamic nucleus and zona incerta in the guinea pig &#8212; Nissl and Golgi study

The studies were carried out on the subthalamus of adult guinea pigs. Golgi impregnation, Nissl and Klüver-Barrera methods were used for the study. In Nissl stained sections the subthalamic neuronal population consists of multipolar, fusiform, oval and pear-shaped perikarya. In two studied areas: nucleus subthalamicus (STN) and zona incerta (ZI) three types of neurons were distinguished. Type I, multipolar neurons with quadrangular, triangular or oval perikarya. They have 3&#8211;6 primary dendrites wich run slightly wavy and spread out in all directions. Type II, bipolar neurons with fusiform or semilunar perikarya, they have two primary dendrites. Type III, pear-shaped neurons with 1&#8211;2 dendritic trunks arising from one pole of the neuron. In all types of neurons axon emerges from the perikaryon or initial segment of a dendritic trunk and can be followed at a maximum distance of about 50 &#956;m

The neuronal structure of the medial geniculate body in the pig - Nissl and Golgi study

The studies were carried out on the brains of adult pigs. The preparations were made by means of the Golgi technique as well as the Nissl and Klüver-Barrera methods. Four types of neurons were described in the medial geniculate body (MGB) of the pig: 1. Multipolar neurons (perikarya 30&#8211;45 &micro;m) with rounded, oval or quadrangular perikarya from which arise 4-7 dendritic trunks. The dendrites divide dichotomically twice, may send out collaterals and give off ramifications. The dendritic branches possess varicosities and knob-like spines. These neurons predominate in MGB. 2. Pear-shaped neurons (20-35 &micro;m) with one or two dendritic trunks arising from one pole of the cell body. These dendrites have a tufted appearance. 3. Triangular neurons (30-45 &micro;m) possess three thick dendrites which first bifurcate near the soma and then divide profusely into daughter branches. 4. Fusiform neurons (30-50 &micro;m) have usually two dendritic trunks which arise from the opposite poles of the cell body and divide dichotomically twice. The fusiform neurons are the least numerous in MGB. Most MGB neurons have on the secondary tertiary dendrites and on their ramifications have delicate varicose or bead-like appendages and spine-like protrusions. In all types of neurons an axon arises either from the soma or from the initial portion of the dendritic trunk

The neuronal structure of the ventromedial and infundibular nuclei in the guinea pig: Nissl and Golgi study

The studies were carried out on the mesencephalons of adult guinea pigs. On the basis of the Golgi technique, as well as the Nissl and Klüver-Barrera methods, four types of neurons were distinguished in the ventromedial nucleus (VMH) and infundibular nucleus (Ni): 1. Rounded neurons (perikarya 12&#8211;18 &micro;m) with 3-4 dendritic trunks, which divide once, twice or not at all. The dendritic branches possess varicosities and knob-like spines. These neurons predominate in VMH. 2. Fusiform neurons (perikarya 15-28 &micro;m) with 2 dendritic trunks, which arise from the opposite poles of the cell body. Bead-like protuberances and knob-like processes are observed on the dendrites. These neurons are the most numerous in Ni. 3. Triangular neurons (perikarya 15-22 &micro;m) possess three thick, conical dendrites, which bifurcate dichotomically. Bead-like appendages and knob-like processes were seen on the dendritic surface. 4. Multipolar neurons (perikarya 18-22 &micro;m) with 4-5 dendritic trunks, which are poorly ramified. The dendritic branches are smooth, but varicosities can be observed on their surface. In all types of neurons an axon was observed to arise either from the dendritic trunk or from the soma