A reliable method for Golgi staining of retina and brain slices

Quantification of Neuronal Dendritic Spine Density and Lengths of Apical and Basal Dendrites in Temporal Lobe Structures Using Golgi-Cox Staining

The objective of this chapter is to provide an overview of the methods used to investigate the connectivity and structure of the nervous system. These methods allow neuronal cells to be categorized according to their location, shape, and connections to other cells. The Golgi-Cox staining gives a thorough picture of all significant neuronal structures found in the brain that may be distinguished from one another. The most significant characteristic is its three-dimensional integrity since all neuronal structures may be followed continuously from one part to the next. Successions of sections of the brain's neurons are seen with the Golgi stain. The Golgi method is used to serially segment chosen brain parts, and the resulting neurons are produced from those sections.

Ginkgo biloba protects striatal neurodegeneration and gut phagoinflammatory damage in rotenone-induced mice model of Parkinson's disease: Role of executioner caspase-3/Nrf2/ARE signaling

Asymptomatic and early clinical stages of Parkinson's disease (PD) have been linked with comorbid non-motor symptoms including dysfunction of the gastrointestinal (GI) tract. Notwithstanding, neuroprotective and gastroprotective effects of Ginkgo biloba supplements (GBS) have been investigated independently. Hence, whether GBS-mediated GIT-protective capacity could be helpful in PD via gut-brain anti-inflammatory signaling still remains unknown. Treatment with GBS significantly repressed the motor behavioral and neuromuscular deficits and prevented loss of striatal dopaminergic loss by improving the level of tyrosine hydroxylase enzyme and suppressing synucleinopathy development. Striatal neurons and ileal epithelial injury following intraperitoneal rotenone administration were accompanied with oxidoinflammatory/nitroinflammatory stress and marked inhibition of cholinergic transmission. Moreover, there was increased striatal executioner caspase-3 and decreased nuclear factor erythroid-2-related factor 2 (Nrf2) immunoexpression, loss of striatal pyramidal neuron with a marked decrease in length and width of the dendritic spines as well as significant hyperplasia of cryptal cells in the ileal epithelial tissues, all which were reversed by the pretreatment + concurrent (Pre-CONC) and concurrent (CONC) GBS treatment pattern. In sum, we proved the potential dual effects of GBS in preventing both dopaminergic neural-related impairments and gut wall abnormalities linked with PD.

Gingko biloba abrogate lead-induced neurodegeneration in mice hippocampus: involvement of NF-κB expression, myeloperoxidase activity and pro-inflammatory mediators

Neuroimmune alterations have important implication in the neuropsychiatric symptoms and biochemical changes associated with lead-induced neurotoxicity. It has been suggested that inhibition of neuroinflammatory-mediated lead-induced neurotoxicity by phytochemicals enriched with antioxidant activities would attenuate the deleterious effects caused by lead. Hence, this study investigated the neuroinflammatory mechanism behind the effect of Ginkgo biloba supplement (GB-S) in lead-induced neurotoxicity in mice brains. Mice were intraperitoneally pretreated with lead acetate (100 mg/kg) for 30 min prior the administration of GB-S (10 and 20 mg/kg, i.p.) and ethylenediaminetetraacetic acid (EDTA) (50 mg/kg, i.p.) for 14 consecutive days. Symptoms of neurobehavioral impairment were evaluated using open field test (OFT), elevated plus maze (EPM), and tail suspension test (TST) respectively. Thereafter, mice brain hippocampi were sectioned for myeloperoxidase activity (MPO), pro-inflammatory cytokine (TNF-α and IL-6) estimation and inflammatory protein (NF-κB) expression. Furthermore, histomorphormetric studies (Golgi impregnation and Cresyl violet stainings) were carried out. GB-S (10 and 20 mg/kg) significantly restores neurobehavioral impairments based on improved locomotion, reduced anxiety- and depressive-like behavior. Moreover, GB-S reduced the MPO activity, inhibits TNF-α, IL-6 release, and downregulates NF-κB immunopositive cell expression in mice hippocampus. Histomorphometrically, GB-S also prevents the loss of pyramidal neuron in the hippocampus. The endpoint of this findings suggest that GB-S decreases neuropsychiatric symptoms induced by lead acetate through mechanisms related to inhibition of release of pro-inflammatory mediators and suppression of hippocampal pyramidal neuron degeneration in mice.

Methyl jasmonate ameliorates rotenone-induced motor deficits in rats through its neuroprotective activity and increased expression of tyrosine hydroxylase immunopositive cells

Decreased tyrosine hydroxylase (TH) activity, due to degeneration of dopaminergic neurons contributes to the low dopamine content and the motor deficits that characterized Parkinson's disease (PD). This study examines the effect of methyl jasmonate (MJ), a neuroprotective bioactive compound isolated from jasminum grandiflorum, on motor functions, immunopositive cells of TH, dendritic neurons and dopamine contents in rotenone (Rot)-treated rats. Rats pretreated daily with MJ (100 mg/kg, i.p) for 21 days also received Rot (2.5 mg/kg, i.p.) 30 min after each pretreatment for every 48 h for 21 days. Motor functions were assessed on day 22. The specific brain regions of the rats were processed for determination of dopamine contents, immunopositive cells of TH, neuronal cell morphology and dendritic aborizations. Rot impaired locomotion and rearing behavior, and decreased dopamine content in the striatum, prefrontal cortex and midbrain. It further reduced the expression of TH in the substantia nigra and striatum relative to vehicle-control (p < 0.05). Histopathologic studies revealed that Rot-treated rats had degenerated neurons with pyknotic nuclei and loss of nigrostriatal neuronal cells. Rot also altered the nigrostriatal dendritic neuronal networks, decreased the dendritic length and spine density. However, pretreatment with MJ improved motor deficits, increased TH activity and dopamine contents in the specific brain regions of Rot-treated rats. MJ also attenuated the cyto-architectural distortions, loss of neuronal cells and dendritic aborizations of the striatum of Rot-treated rats. These findings suggest that MJ may reverse the motor deficits associated with PD by modifying the key pathological abnormalities involved in the disease progression.

Morin decreases cortical pyramidal neuron degeneration via inhibition of neuroinflammation in mouse model of schizophrenia

Neuroinflammation plays a prominent role in the pathophysiology and progression of schizophrenia. Thus, suppression of neuroinflammation may retard the progression of the disease. This study was designed to investigate whether morin, a bioactive compound with antipsychotic-like activity could reduce biomarkers of neuroinflammation and neurodegeneration in lipopolysaccharide (LPS)- and ketamine (KET)-induced schizophrenic-like behavior in mice. Animals were treated once daily intraperitoneally with morin (100 mg/kg), haloperidol (1 mg/kg), risperidone (0.5 mg/kg), or saline (10 mL/kg) in combination with LPS (0.1 mg/kg) for 14 consecutive days. However, from days 8-14, overt schizophrenia-like episode was produced with i.p. injection of KET (20 mg/kg) once daily. Schizophrenic-like behaviors: positive (open-field test), negative (social-interaction and social-memory tests) and cognitive (Y-maze test) symptoms were assessed on day 14. Thereafter, the levels and expressions of biomarkers of neuroinflammation were estimated in the striatum (ST), prefrontal cortex (PFC) and hippocampus (HC) using spectrophotometry, ELISA and immunohistochemistry. The effects of morin on cortical pyramidal neurons were estimated using Golgi-impregnation staining technique. LPS in combination with KET significantly (p < 0.05) induced schizophrenia-like behaviors, which was attenuated by morin. Morin significantly (p < 0.05) decreased tumor necrosis factor-α, interleukine-6 levels and myeloperoxidase activity in the ST, PFC and HC of mice treated with LPS + KET. Moreover, morin reduced regional brain expressions of cyclooxygenase-2, inducible nitric oxide synthase and nuclear factor kappa-B, and also rescued loss of pyramidal neurons in the PFC. Taken together, these findings suggest that morin reduces schizophrenic-like symptoms induced by LPS + KET via mechanisms related to inhibition of the release of pro-inflammatory mediators and suppression of degeneration of cortical pyramidal neurons in mice.

An update on the Golgi staining technique improving cerebellar cell type specificity

The detailed morphological characterization of single cells was a major breakthrough in neuroscience during the turn of the twentieth century, enabling Ramon y Cajal to postulate the neuron doctrine. Even after 150 years, single cell analysis is an intriguing goal, newly motivated by the finding that autism might be caused by intricate and discreet changes in cerebellar morphology. Besides new single labelling technologies, the Golgi staining technique is still in use due to its whole cell labelling characteristics, its superior contrast performance over other methods and its apparent randomness of staining cells within a whole tissue block. However, the specificity and whole cell labelling of Golgi staining are also disputed controversially, and the method still has a poor reputation for being time consuming and needing high expenditures. We demonstrate here, how a classical Golgi technique can be adapted for staining different cerebellar cell types using a time-saving and efficient protocol, enabling the identification of the detailed morphological characteristics of single cells.

Golgi-Cox Staining Step by Step

Golgi staining remains a key method to study neuronal morphology in vivo. Since most protocols delineating modifications of the original staining method lack details on critical steps, establishing this method in a laboratory can be time-consuming and frustrating. Here, we describe the Golgi-Cox staining in such detail that should turn the staining into an easily feasible method for all scientists working in the neuroscience field.

Increased anatomical detail by in vitro MR microscopy with a modified Golgi impregnation method

Golgi impregnation is unique in its ability to display the dendritic trees and axons of large numbers of individual neurons by histology. Here we apply magnetic resonance microscopy to visualize the neuroanatomy of animal models by combining histologic fixation chemistry with paramagnetic contrast agents. Although there is some differential uptake of the standard small-molecular-weight contrast agents by different tissue types, detailed discrimination of tissue architecture in MR images does not approach that of standard histology. Our modified Golgi impregnation method significantly increases anatomic detail in magnetic resonance microscopy images. Fixed mouse brains were treated with a solution containing a paramagnetic contrast agent (gadoteridol) and potassium dichromate. Results demonstrate a specific contrast enhancement likely due to diamagnetic hexavalent chromium undergoing tissue specific reduction to paramagnetic trivalent chromium. This new method dramatically improves neuroanatomical contrast compared to conventional fixation, displaying detail approximating that of histologic specimens at low (4x) magnification.

Morphometric analysis in neurodegenerative disorders

The study of dendritic length and spine density has become a standard in the analysis of neuronal abnormalities since a considerable number of neurological diseases have their foundation in alterations in these structures. One of the best ways to study possible alterations in neuronal morphometry is the use of Golgi impregnation. Introduced more than a century ago, it is still the standard and state-of-the-art technique for visualization of neuronal architecture. We successfully applied the Golgi method to mouse, rat, monkey and human brain tissues for studying both the normal and abnormal morphology of neurons. We were able to discover subtle morphological alterations in neuronal dendrites and dendritic spines in different brain areas. Although Golgi preparations can be examined by electronic microscopy, we used light microscopy and Neurolucida reconstruction to quantitatively explore the relationship between total dendritic length and spine density in different types of neurons. This review summarizes the methodology used to quantify neuronal abnormalities and discusses the utility of these techniques in different models of neurodegeneration.

A rapid method combining Golgi and Nissl staining to study neuronal morphology and cytoarchitecture

The Golgi silver impregnation technique gives detailed information on neuronal morphology of the few neurons it labels, whereas the majority remain unstained. In contrast, the Nissl staining technique allows for consistent labeling of the whole neuronal population but gives very limited information on neuronal morphology. Most studies characterizing neuronal cell types in the context of their distribution within the tissue slice tend to use the Golgi silver impregnation technique for neuronal morphology followed by deimpregnation as a prerequisite for showing that neuron's histological location by subsequent Nissl staining. Here, we describe a rapid method combining Golgi silver impregnation with cresyl violet staining that provides a useful and simple approach to combining cellular morphology with cytoarchitecture without the need for deimpregnating the tissue. Our method allowed us to identify neurons of the facial nucleus and the supratrigeminal nucleus, as well as assessing cellular distribution within layers of the dorsal cochlear nucleus. With this method, we also have been able to directly compare morphological characteristics of neuronal somata at the dorsal cochlear nucleus when labeled with cresyl violet with those obtained with the Golgi method, and we found that cresyl violet-labeled cell bodies appear smaller at high cellular densities. Our observation suggests that cresyl violet staining is inadequate to quantify differences in soma sizes.

A modified Golgi staining protocol for use in the human brain stem and cerebellum

The Golgi silver-impregnation method established itself as an important technique for distinguishing morphology at the individual neuron level. This technique has been especially useful for studying human neuroanatomy because it works on postmortem tissue but it is also unreliable and capricious. In this report, we describe a simple technique that was applied to human autopsy and tissue-bank material yielding useful results for the study of neuronal morphology in the brain stem and cerebellum. Human adult brain stems had been immersion-fixed in formalin for a period of time ranging from weeks to months. Brain stem tissue was cross-sectioned into 3-5mm thick slabs, centered about the cochlear nucleus. Slabs were processed under continuous vacuum (22-26 in. of Hg), a procedure that promoted penetration of reagents into the tissue. Tissue was sectioned using a Vibratome and mounted for light microscopy. The results demonstrated improved staining of neurons in the brain stem. Staining of the large synaptic endings of auditory nerve fibers called end bulbs of Held in the cochlear nucleus was especially evident. These results suggest that an age-graded series could be conducted to describe the development of these large auditory endings in humans.

Chronic corticotropin-releasing factor type 1 receptor antagonism with antalarmin regulates the dopaminergic system of Fawn-Hooded rats

Corticotropin-releasing factor is a neuropeptide associated with the integration of physiological and behavioural responses to stress and also in the modulation of affective state and drug reward. The selective, centrally acting corticotropin-releasing factor type 1 receptor antagonist, antalarmin, is a potent anxiolytic and reduces volitional ethanol consumption in Fawn-Hooded rats. The efficacy of antalarmin to reduce ethanol consumption increased with time, suggestive of adaptation to reinforcement processes and goal-directed behaviour. The aim of the present study was to examine the effects of chronic antalarmin treatment on reward-related regions of Fawn-Hooded rat brain. Bi-daily antalarmin treatment (20 mg/kg, i.p.) for 10 days increased tyrosine hydroxylase messenger RNA expression throughout the ventral mesencephalon. Following chronic antalarmin the density of dopaminergic terminals within the basal ganglia and amygdaloid complex were reduced, as was dopamine transporter binding within the striatum. Receptor autoradiography indicated an up-regulation of dopamine D2, but no change in D1, binding in striatum, and Golgi-Cox analysis of striatal medium spiny neurones indicated that chronic antalarmin treatment increased spine density. Thus, chronic antalarmin treatment modulates dopaminergic pathways and implies that chronic treatment with drugs of this class may ultimately alter postsynaptic signaling mechanisms within the basal ganglia.

Optimization of Golgi methods for impregnation of brain tissue from humans and monkeys

Golgi impregnation is unique in its ability to display the dendritic trees of large numbers of individual neurons. However, its reputation for inconsistency leaves many investigators reluctant to embrace this methodology, particularly for the study of formalin-fixed human brain tissue. After reviewing the literature, testing a variety of technical variations, and discussing the procedure with experienced practitioners, we have concluded that much of the unpredictability can be removed by matching the Golgi technique to the conditions that were used for fixation of the tissue. Briefly fixed tissues worked best with the rapid Golgi technique, which includes osmium during the initial chromation step, and with the Golgi-Cox method, which includes mercuric chloride during chromation. For tissues that have been fixed for several years or even for several decades, superior results are obtained with the Golgi-Kopsch technique, using multiple changes of a chromation solution that contains paraformaldehyde. In the Golgi-Kopsch technique, pH should be used to monitor the reduction of Cr6+ to Cr3+, which is a crucial determinant of successful chromation. With any Golgi technique, agitation throughout the impregnation helps to avoid precipitates and to improve the quality of impregnation. When the appropriate method is chosen, Golgi impregnation is a useful technique for the neuropathologist.

Abnormal function of astroglia lacking Abr and Bcr RacGAPs

Experiments in cultured cells have implicated the molecular switch Rac in a wide variety of cellular functions. Here we demonstrate that the simultaneous disruption of two negative regulators of Rac, Abr and Bcr, in mice leads to specific abnormalities in postnatal cerebellar development. Mutants exhibit granule cell ectopia concomitant with foliation defects. We provide evidence that this phenotype is causally related to functional and structural abnormalities of glial cells. Bergmann glial processes are abnormal and GFAP-positive astroglia were aberrantly present on the pial surface. Older Abr;Bcr-deficient mice show spontaneous mid-brain glial hypertrophy, which can further be markedly enhanced by kainic acid. Double null mutant astroglia are hyper-responsive to stimulation with epidermal growth factor and lipopolysaccharide and exhibit constitutively increased phosphorylation of p38 mitogen-activated protein kinase, which is regulated by Rac. These combined data demonstrate a prominent role for Abr and Bcr in the regulation of glial cell morphology and reactivity, and consequently in granule cell migration during postnatal cerebellar development in mammals.