The cholinergic system of basal forebrain (nucleus basalis, NB) has been implicated in important cognitive functions such as arousal, attention, and memory, yet little is known of how this system affects cortical processing. Previous studies have shown that NB stimulation causes bi-directional changes in the overall firing rate of cortical neurons. Additionally, the laminar distributions of different subtypes of acetylcholine (ACh) receptors suggest that ACh can selectively boost feedforward thalamocortical inputs while suppressing recurrent intracortical interactions. Thus, although cortical cholinergic input does not carry sensory information, it may act to modulate neural excitability and effective connectivity in the cortex. These changes in the cortical circuit may in turn affect visual processing by dynamically altering cortical receptive field (RF) properties. I have generated a series of hypotheses on the effect of NB stimulation on visual cortical RFs. In the proposed project, I will test these hypotheses by stimulating the NB while making multielectrode recordings from neurons in the adult rat visual cortex. Specifically, I will characterize the effects of NB stimulation on (i) V1 orientation tuning, direction selectivity, and spatiotemporal receptive field (STRF) properties (ii) spatial phase sensitivity of visual responses (which differs between simple and complex cells), and (iii) response characteristics to natural scenes. Determining the effects of NB stimulation on cortical RFs will provide important insights into the modulation of ongoing sensory processing that potentially underlies higher-level cognitive processes.

Public Health Relevance

Nucleus Basalis is one of the first and most severely damaged areas affected by Alzheimer's disease. Thus, understanding what effect it has on sensory processing represents an important step in understanding the pathologies associated with Alzheimer's disease. The proposed research will elucidate the receptor types involved in specific changes to sensory processing as well as suggest potential treatment strategies using pharmacological agents. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31NS059258-01A2
Application #
7546679
Study Section
Special Emphasis Panel (ZRG1-F02B-B (20))
Program Officer
Gnadt, James W
Project Start
2008-08-01
Project End
2010-07-31
Budget Start
2008-08-01
Budget End
2009-07-31
Support Year
1
Fiscal Year
2008
Total Cost
$31,294
Indirect Cost
Name
University of California Berkeley
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Pinto, Lucas; Goard, Michael J; Estandian, Daniel et al. (2013) Fast modulation of visual perception by basal forebrain cholinergic neurons. Nat Neurosci 16:1857-1863
Goard, Michael; Dan, Yang (2009) Basal forebrain activation enhances cortical coding of natural scenes. Nat Neurosci 12:1444-9