Emory University

About: Emory University is a education organization based out in Atlanta, Georgia, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 51959 authors who have published 122469 publications receiving 6010698 citations.

Targeting abnormal neural circuits in mood and anxiety disorders: from the laboratory to the clinic

Abstract: Recent decades have witnessed tremendous advances in the neuroscience of emotion, learning and memory, and in animal models for understanding depression and anxiety. This review focuses on new rationally designed psychiatric treatments derived from preclinical human and animal studies. Nonpharmacological treatments that affect disrupted emotion circuits include vagal nerve stimulation, rapid transcranial magnetic stimulation and deep brain stimulation, all borrowed from neurological interventions that attempt to target known pathological foci. Other approaches include drugs that are given in relation to specific learning events to enhance or disrupt endogenous emotional learning processes. Imaging data suggest that common regions of brain activation are targeted with pharmacological and somatic treatments as well as with the emotional learning in psychotherapy. Although many of these approaches are experimental, the rapidly developing understanding of emotional circuit regulation is likely to provide exciting and powerful future treatments for debilitating mood and anxiety disorders.

The Theory of the Firm and the Structure of the Franchise Contract

Abstract: Uses the tools of Coase's (1937) theory of the firm, and an analysis of property rights, incentives and monitoring, to assess the nature of the franchise contract. Franchising is of interest to economists because it represents a situation in which there is not a sharp distinction between interfirm and intrafirm transactions. The institutional structure of the franchise is discussed, and a franchise agreement is defined as a contract between two legal firms--the franchisor, or parent company, and the franchisee, a firm set up in a specific location to market the product or service offered by the parent company. The franchisee pays a specific amount of money for the right to market this product or service. The standard explanation of franchising, in terms of capital markets, is then considered and rejected. The theory debated is that franchisors use franchising as a means to raise capital. However, by considering this argument in light of modern capital theory, it is concluded that the franchisor interested in raising capital would do better to create a portfolio of shares in many franchise outlets in order to diversify risks and maximize profit potential. An alternative explanation of franchisee motivations is given which suggests that both parts of the contract give property rights to the parties, i.e., the franchisor and the franchisee, for areas they can most efficiently control. Finally, the application of antitrust law to franchising is found to be false, since it confuses legal categories with economically meaningful ones. (SFL)

Stimulation of the Subthalamic Nucleus Changes the Firing Pattern of Pallidal Neurons

Abstract: To clarify the mechanism underlying improvement of parkinsonian signs by high-frequency electrical stimulation (HFS) of the subthalamic nucleus (STN), we investigated the effects of STN HFS on neuronal activity of the internal and external segment of the globus pallidus (GPi and GPe, respectively) in two rhesus monkeys rendered parkinsonian by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. A scaled-down version of the chronic stimulating electrode used in humans, consisting of four metal contacts 0.50 mm in length each separated by 0.50 mm, was implanted through a cephalic chamber targeting the STN. Histological reconstruction revealed that the cathode was located in the STN in both monkeys. Extracellular recordings from a total of 110 pallidal neurons during STN stimulation were performed. Poststimulus time histograms of single neurons triggered by 2 Hz STN stimulation pulses at 2.4–3.0 V revealed short-latency excitations at 2.5–4.5 and 5.5–7.0 msec after stimulation onset and inhibitions at 1.0–2.5, 4.5–5.5, and 7.0–9.0 msec for both GPe and GPi neurons. These short-latency responses were present with 136 Hz stimulation, at voltages effective for alleviation of parkinsonian signs, resulting in a significant increase in mean discharge rate and a stimulus-synchronized regular firing pattern. These results indicate that activation of the STN efferent fibers and resultant changes in the temporal firing pattern of neurons in GPe and GPi underlie the beneficial effect of HFS in the STN in Parkinson's disease and further support the role of temporal firing patterns in the basal ganglia in the development of Parkinson's disease and other movement disorders.