A MEG investigation of somatosensory processing in the rhesus monkey.

The use of minimally and non-invasive neuroimaging methods in animal models has sharply increased over the past decade. Such studies have enhanced understanding of the neural basis of the physical signals quantified by these tools, and have addressed an assortment of fundamental and otherwise intractable questions in neurobiology. To date, these studies have almost exclusively utilized positron-emission tomography or variants of magnetic resonance based imaging.

PET imaging of dopamine D2 receptors during chronic cocaine self-administration in monkeys.

Dopamine neurotransmission is associated with high susceptibility to cocaine abuse. Positron emission tomography was used in 12 rhesus macaques to determine if dopamine D2 receptor availability was associated with the rate of cocaine reinforcement, and to study changes in brain dopaminergic function during maintenance of and abstinence from cocaine. Baseline D2 receptor availability was negatively correlated with rates of cocaine self-administration.

Behavioral depression and positron emission tomography-determined serotonin 1A receptor binding potential in cynomolgus monkeys.

Context: Current animal models of depression are inadequate to further our understanding of depression. New models that allow for analysis of cognitive function and sex differences are needed.

Objective: To characterize serotonin 1A (5-HT(1A)) receptor binding potential (BP) and its relationship with specific characteristics of behavioral depression in cynomolgus monkeys.

N-[18F]4'-fluorobenzylpiperidin-4yl-(2-fluorophenyl) acetamide ([18F]FBFPA): a potential fluorine-18 labeled PET radiotracer for imaging sigma-1 receptors in the CNS.

A series of brain uptake studies and PET imaging studies were conducted with the sigma(1) selective imaging agent, [(18)F]FBFPA. The results of the study indicate that this radiotracer readily crosses the blood-brain barrier and labels sigma(1) receptors in vivo. In vivo blocking studies with a sigma(1) selective ligand and a nonselective sigma(1)/sigma(2) receptor ligand indicates that [(18)F]FBFPA labels sigma(1) and not sigma(2) receptors in rodent brain.

Neuroimaging of rodent and primate models of alcoholism: initial reports from the integrative neuroscience initiative on alcoholism.

Neuroimaging of animal models of alcoholism offers a unique path for translational research to the human condition. Animal models permit manipulation of variables that are uncontrollable in clinical, human investigation. This symposium, which took place at the annual meeting of the Research Society on Alcoholism in Vancouver, British Columbia, Canada, on June 29th, 2004, presented initial findings based on neuroimaging studies from the two centers of the Integrative Neuroscience Initiative on Alcoholism funded by the National Institute on Alcohol Abuse and Alcoholism.

Evaluation of the quantitative capability of a high-resolution positron emission tomography scanner for small animal imaging.

Objective: The quantitative capability of a positron emission tomography scanner for small animal imaging was evaluated in this study.

Methods: The microPET P4 (Concorde Microsystems, Knoxville, TN) scanner's capability for dynamic imaging and corrections for radioactive decay, dead time, and attenuation were evaluated. Rat brain and heart studies with and without attenuation correction were compared.

Neurofunctional imaging of the pancreas utilizing the cholinergic PET radioligand [18F]4-fluorobenzyltrozamicol.

The pancreas is one of the most heavily innervated peripheral organs in the body. Parasympathetic and sympathetic neurons terminate in the pancreas and provide tight control of endocrine and exocrine functions. The aim of this study was to determine whether the pancreas can be imaged with a radioligand that binds to specific neuroreceptors.

Social dominance in monkeys: dopamine D2 receptors and cocaine self-administration.

Disruption of the dopaminergic system has been implicated in the etiology of many pathological conditions, including drug addiction. Here we used positron emission tomography (PET) imaging to study brain dopaminergic function in individually housed and in socially housed cynomolgus macaques (n = 20). Whereas the monkeys did not differ during individual housing, social housing increased the amount or availability of dopamine D2 receptors in dominant monkeys and produced no change in subordinate monkeys.

[[(18)F]N-(4'-fluorobenzyl)-4-(3-bromophenyl) acetamide for imaging the sigma receptor status of tumors: comparison with [(18)F]FDG, and [(125)I]IUDR.

A series of biodistribution studies were conducted with the radiotracer, [(18)F]N-(4'-fluorobenzyl)-4-(3-bromophenyl)acetamide, [(18)F]1 in nude mice bearing tumor xenografts of the mouse mammary adenocarcinoma, line 66. This radiotracer has a high affinity for both sigma(1) and sigma(2) receptors. In vivo studies were also conducted in order to assess the effect of blocking sigma(1) receptors on tumor uptake and the tumor:background ratio of this radiotracer.