OUR SERVICES & APPLICATIONS
Integrating neuronal dendritic and synaptic morphology with advanced analytics to illuminate the brain’s neuroresilience and vulnerability.
Our Mission:
Excellence in Collaborative Contract Research
Without Compromise
Hippocampal CA3 neuron
Cortical Pyramid
WHAT WE DO:
JUST SEND US FIXED BRAINS…We do everything else !
Using the formalin fixed brain tissue sent to our lab, Nirvana Neuroscience
specializes in:
Golgi-impregnation staining of neurons and preparation of coded slides followed by highly computerized and AI-assisted microscopic
analyses of :
Dendritic Branching — provides measures of dendritic lengths and domain complexity.
Dendritic Spines — computerized counting and categorizing of dendritic spines of the Golgi impregnated neurons.
Our Stereology Services provide unbiased estimates of the number of neurons and volume of a defined brain region. Stereology used as an adjunct procedure to the Golgi studies can provide significant insight into the relevance of the Golgi data. This is available upon request.
All neuronal and dendritic analyses are carried out on coded slides using the latest computer- and AI-assisted software and hardware to mitigate human error and biases.
In addition to intermediate updates of the status of the study, a final report will include a complete statistical analysis with appropriate graphics, photomicrographs, and a discussion of the results.
HERE ARE SOME SCENARIOS FOR APPLICATION OF OUR SERVICES
- Animal Models of Brain Aging and Alzheimer’s Disease: assessing the efficacy of putative prophylactic or therapeutic treatment strategies on the health and integrity of neural circuitry
- Transgenic and Knockout Mouse Models
- Traumatic brain injury/CTE/Concussion-related brain injury
- Dietary manipulation of brain development and aging
- Extrinsic environmental or intrinsic genetic factors influencing brain development, maturation, and aging
- Effects of putative neurotoxins
- Effects of pharmaceuticals on learning and memory
HERE ARE A FEW EXAMPLES OF OUR ANALYSES
DENDRITIC BRANCHING ANALYSIS
Dendritic branching analysis data includes:
1. Estimated total dendritic length,
2. Distribution of the dendritic arbor,
3. Complexity of the dendritic tree.
4. soma size
Evaluating the Amount of Dendritic Branching from Golgi-Stained Neurons.
Example 1: Dendritic Alterations in an Animal Model of Alzheimer’s Disease.
(Below --Photomicrograph of a hippocampal CA1 pyramid from a wild type control mouse )
Below: CA1 basilar trees from normal wild type mouse (above) and from a mouse model of Alzheimer’s Disease (below), a transgenic Arc A-beta mouse.
In the graph below, comparison of the complexity of the dendritic fields of the CA1s based on the number of dendritic branch points also shows significant reduction of dendritic complexity in this mouse model of AD. The graph compares the complexity of CA1 basilar dendritic trees from 3 month-old wild type control mice (blue) vs CA1s from an age-matched Arc A-beta mouse model of AD (red). The neurons from the AD mouse model have significantly fewer branch points than the WT controls; as such, the dendritic arbor of the AD mouse CA1s is less complex.
In the graph below, we have the results of the Sholl Analysis, which compares the amount of dendritic material at increasing distances from the cell body. This is determined from the number of intersections with a series of concentric circles originating at the center of the soma. Here, it is clearly seen that the dendritic arbor of the transgenic AD mouse CA1 neurons (basilar tree) is significantly less than that of the age-matched wild-type (WT) controls.
Example 2: Environmental/Dietary Studies --
A Blueberry-Enriched Diet Reverses Age-related Neocortical Dendritic Branch Loss in Old Rats
The graph above shows how dietary ingredients can influence dendritic branching – in this case, the effects of a blueberry enriched diet on age-related changes of neurons in the rat neocortex. The Sholl graph below demonstrates that there is a significant decrease in dendritic branching with normal aging (young control profile [top] vs. the old control [bottom]). Treatment of older rats with a blueberry-enriched diet for 3 months increased the amount of the dendritic branching in the cortical pyramids (middle profile) such that it was now not significantly less than in the young mice. This shows that normal age-related loss of the dendritic arbor can be ameliorated by dietary means, thus maintaining the more youthful brain circuitry.
Representative photomicrographs of layer II/III pyramids of the parietal cortex (basilar tree) from an old control rat (left) and from an old age-matched rat which had received a blueberry enriched diet (right).
Example 3: Neurotoxicology Studies
Neonatal exposure to PCBs results in reduced dendritic arbor in hippocampal CA1s of 22 do rat pups.
Neonatal Exposure to PCBs results in early – but reversible – damage to Purkinje Cells of the Cerebellum of the Rat
Appearance of Golgi stained Purkinje cells in Rat Cerebellum
A. Measurement of area of representative Purkinje Cell dendritic arbor (22 days-old).
B. Purkinje cell arbor of 22 day-old rats exposed to PCBs is significantly smaller than age-matched
controls.
C. Dendritic arbor of Purkinje cell from adult (60 day-old) rat cerebellum.
D. Purkinje cell dendritic arbor of 60 day old rat which had been exposed neonatally to PCBs.
The values for these 4 groups are seen in the bar graph to the right of the photomicrographs. Note the significantly smaller Purkinje Cell areas in the 22do PCB group. However, by 60 do this early damage is mitigated and the Purkinje cells of both groups are equivalent.
Example 4: Neuropathology
Normal appearing hippocampal CA1 from non-cognitively impaired 80 year old.
Atrophic CA1 pyramid seen in autopsied hippocampal tissue from Alzheimer brain (86 years old).
DENDRITIC SPINE ANALYSIS
Our Dendritic Spine Analysis Studies include assessment of:
• Spine Density
• Spine Configurations
The vast majority of synapses occur on dendritic spines. It is fairly obvious that spine density can be affected by various extrinsic, genetic, or pathological factors such as Alzheimer’s Disease, brain injury, or Down syndrome and that synaptic/spine loss or deficit is readily associated with some degree of cognitive dysfunction.
However, it is also relevant that spine configuration plays a more subtle, albeit significant, role in synaptic function. For example, so-called Mushroom shaped spines (large head, thin neck) are associated with long-term memory. Some of these observations are poorly understood, but additional studies may help to elucidate a stronger structural-functional relationship.
Example 1: Reduction of Dendritic Spines in Hyperglycemic Rats
The graph below shows the spine density on granule cells of the rat dentate gyrus.
Hyperglycemic rats show significant spine loss compared to controls and hypoglycemic rats.
The photomicrographs below show the appearance of spines from controls and hyperglycemic rats:
Example 2: Loss of Dendritic Spines in the Progression of Alzheimer’s Disease Normal appearing hippocampal CA1 from non-cognitively impaired 80 year old.
Normal Aging (Non-Cognitively Impaired
Mild Cognitive Impairment (MCI)
Alzheimer’s Disease
Progressive Spine Loss in the Evolution of Alzheimer’s Disease
Example 3: Extrinsic Influences on Dendritic Spine
CA1 pyramids: loss of M-type spines (% change from control)
Example 4: Traumatic Brain Injury
Example 5. Cerebral Ischemia
Note the appearance of numerous long filopodia-like spines.
