The Isotropic Fractionator: A Fast, Reliable Method to Determine Numbers of Cells in the Brain or Other Tissues

2011 ◽  
pp. 391-403 ◽  
Author(s):  
Suzana Herculano-Houzel
Keyword(s):  
Reliable Method ◽  
Isotropic Fractionator ◽  
The Brain

A simple and reliable method for delivering small fluid volumes to the brain of a freely moving rat

1997 ◽  
Vol 72 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Gary W Hesse ◽  
James R Stellar ◽  
Jessica Chevrette
Keyword(s):  
Reliable Method ◽  
Freely Moving ◽  
The Brain

scholarly journals Peeking Inside the Lizard Brain: Neuron Numbers in Anolis and Its Implications for Cognitive Performance and Vertebrate Brain Evolution

2020 ◽  
Author(s):  
Levi Storks ◽  
Brian J Powell ◽  
Manuel Leal
Keyword(s):  
Cognitive Performance ◽  
Brain Size ◽  
Motor Task ◽  
Behavioral Flexibility ◽  
Brain Evolution ◽  
Relative Mass ◽  
Published Data ◽  
Vertebrate Brain ◽  
Isotropic Fractionator ◽  
The Brain

Abstract Studies of vertebrate brain evolution have mainly focused on measures of brain size, particularly relative mass and its allometric scaling across lineages, commonly with the goal of identifying the substrates that underly differences in cognition. However, recent studies on birds and mammals have demonstrated that brain size is an imperfect proxy for neuronal parameters that underly function, such as the number of neurons that make up a given brain region. Here we present estimates of neuron numbers and density in two species of lizard, Anolis cristatellus and A. evermanni, representing the first such data from squamate species, and explore its implications for differences in cognitive performance and vertebrate brain evolution. The isotropic fractionator protocol outlined in this article is optimized for the unique challenges that arise when using this technique with lineages having nucleated erythrocytes and relatively small brains. The number and density of neurons and other cells we find in Anolis for the telencephalon, cerebellum, and the rest of the brain (ROB) follow similar patterns as published data from other vertebrate species. Anolis cristatellus and A. evermanni exhibited differences in their performance in a motor task frequently used to evaluate behavioral flexibility, which was not mirrored by differences in the number, density, or proportion of neurons in either the cerebellum, telencephalon, or ROB. However, the brain of A. evermanni had a significantly higher number of nonneurons and a higher nonneuron to neuron ratio across the whole brain, which could contribute to the observed differences in problem solving between A. cristatellus and A. evermanni. Although limited to two species, our findings suggest that neuron number and density in lizard brains scale similarly to endothermic vertebrates in contrast to the differences observed in brain to body mass relationships. Data from a wider range of species are necessary before we can fully understand vertebrate brain evolution at the neuronal level.

Trauma-hemorrhage and resuscitation in the mouse: effects on cardiac output and organ blood flow

1993 ◽  
Vol 264 (4) ◽  
pp. H1166-H1173 ◽  
Author(s):  
P. Wang ◽  
Z. F. Ba ◽  
J. Burkhardt ◽  
I. H. Chaudry
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Reliable Method ◽  
Sham Operation ◽  
Organ Blood Flow ◽  
Radioactive Microspheres ◽  
Ringer Lactate ◽  
Late Mortality ◽  
The Brain

Although mice are widely used for the study of immune consequences of hemorrhage, the changes of cardiac output (CO) and blood flow (BF) in response to trauma and hemorrhage in this species have not been well defined. To study this, nonheparinized C3H/HeN mice (n = 6 per group) underwent laparotomy (i.e., trauma induced), were bled to a mean arterial pressure of 35 mmHg, and maintained for 90 min by withdrawing more blood or returning Ringer lactate. The animals were then resuscitated with four times the volume of maximal bleedout in the form of Ringer lactate over 60 min. Sham-operated mice underwent the same procedure but were neither bled nor resuscitated. At the end of hemorrhage, 60 min postresuscitation, or corresponding time after sham operation, CO and BF were determined by radioactive microspheres. Results indicate that CO and BF decreased significantly at the end of hemorrhage. Resuscitation, however, restored CO and BF in various organs except the brain and skeletal muscle. Despite this, 9 of 16 mice died within 6 days postresuscitation, whereas none of sham mice died (n = 16 per group in this additional study). Therefore, we have developed a nonheparinized model of trauma-hemorrhage and resuscitation in mice that is associated with late mortality. Furthermore, the microsphere technique provides a reliable method for assessing CO and BF in mice. Thus it may be possible to study the correlation between cardiovascular and immunologic alterations under such conditions.

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