China
Africa
Explore chapters and articles related to this topic
Santiago Ramón y Cajal (1852–1934)
Published in Andrew P. Wickens, Key Thinkers in Neuroscience, 2018
Despite this, the neuron doctrine continued to be strongly criticised by the reticulists led by Golgi, who stuck to their belief that communication between axon fibres took place through continuity and not through direct contact. Indeed, the contact hypothesis was problematical for the neuron doctrine since it was not clear how the nerve impulse (which by now was known to be electrical in nature) could travel from one separate nerve cell to another. In this respect, the Golgi technique offered few clues. The strength of the Golgi stain had been its random selectivity. By only staining a small percentage of nerve cells in any tissue sample, it had made them highly visible for a microscopist to observe. But this was also a weakness when it came to establishing their connections since it was unlikely the stain would highlight two connecting nerve cells. And even if this did occur, the tiny cells of the nervous system meant that visualisation of the contact was beyond the resolution of the microscope of the times. The one exception to this was the much larger neuromuscular junction. Here, the motor fibre and muscle end plate could be seen in greater detail, and in 1886, the German Wilhelm Kühne reported that he could see a clear gap between the two. Kühne conveyed this to the Royal Society of London in 1888, speculating the nerve ending was open in some way, allowing its fluid to escape and cross the tiny gap, before reaching the muscle.
The Nerve Cell Laid Bare
Published in Andrew P. Wickens, A History of the Brain, 2014
In a period barely spanning a decade, Cajal had made a number of fundamental discoveries concerning the structure and function of the nervous system. Perhaps most of all, he had helped establish the neuron doctrine, which recognised the nerve cell as the basic unit of the brain and spinal cord. However, this also led to a baffling and awkward question: how could information flow within an ‘infinitely fragmented’ nervous system, as opposed to a continuous neural reticulum? If the neuron doctrine was correct, then each nerve cell was a separate entity. In other words, the axon and dendrite did not fuse together as reticulum theory demanded (this was also sometimes called the continuity hypothesis). However, the alternative option, otherwise known as the contact hypothesis, was also problematical, since it remained to be known how the impulse travelled from one nerve cell to another across a tiny gap. In this respect, the Golgi technique could offer few clues. The strength of the Golgi stain had been its random selectivity. By only staining a few nerve cells in any tissue sample, it had made them highly visible for a microscopist to observe. This was also a weakness when it came to trying to establish their connections, because it was unlikely the stain would highlight two consecutive nerve cells. Even if this did occur, the visualisation of the contact was beyond the resolution of the light microscope. Thus, the Golgi method, even in the hands of Cajal, was not suitable for revealing how the axon endings terminated with other cells.
The Measurement of Dreams
Published in Milton Kramer, The Dream Experience, 2013
It becomes apparent that a system such as described by Hall and Van de Castle in 1966 could have been a starting point for a common measurement system such as was established for measuring the physiology of sleep (Rechtschaffen & Kales, 1968) with the consequence of encouraging a common metric to foster communication among investigators. Any weakness in the Hall and Van de Castle system such as the relative limitation on identifying emotions in dream reports could be overcome by using an additional carefully constructed system such as the Gottschalk-Gleser Content Analysis Scales (Gottschalk, Winget, & Gleser, 1969). The approach of using complementary scoring systems to measure dream content reports is analogous to the use of different staining techniques used in examining various aspects of the nervous system. The Nissl stain, for example, is used to highlight cell bodies, while the Golgi stain is used to examine axons or dendrites (cell fibers).
Neuronal morphology and synaptic plasticity in the hippocampus of vitamin A deficient rats
Published in Nutritional Neuroscience, 2022
Fabien Dumetz, Rachel Ginieis, Corinne Bure, Anaïs Marie, Serge Alfos, Véronique Pallet, Clémentine Bosch-Bouju
Golgi-Cox staining. Rats (n = 4/group) were deeply anesthetized with isoflurane and brain was removed after decapitation. Four animals per group were used. Brains were processed according to the Golgi-Cox kit guidelines (PK401 FD Rapid Golgi Stain KIT, Neurotechnologies INC, Paris, France) as previously described [26]. Briefly, one hemisphere per brain was immersed in Golgi-Cox A + B solution for 10 days, then in solution C for 2 days before deep frozen in isopentane at −70°C. Brains were stored at −80°C for 6 days. Twelve coronal sections of 200 μm thickness containing the dorsal hippocampus were collected for each rat at −22°C using a cryostat (Leica, Solms, Germany). Two days later, dried slices were stained with solutions D and E, dehydrated and coverslipped with Depex. Light exposure was limited throughout the whole process.
Sitagliptin rescues memory deficits in Parkinsonian rats via upregulating BDNF to prevent neuron and dendritic spine loss
Published in Neurological Research, 2018
Jing Li, Shuhu Zhang, Chenye Li, Mei Li, Lan Ma
FD rapid Golgi stain kit was applied for analyzing spine density. As shown in Figure 4, after sitagliptin administration, the number of spines in every neurite segment significantly increased compared with vehicle group (P < 0.01). This finding indicated sitagliptin had a neuroprotective effect to prevent dendritic spine loss.