Distinct populations of cortical pyramidal neurons mediate drug reward and aversion.

Processing within the anterior cingulate cortex (ACC) is crucial for the patterning of appropriate behavior, and ACC dysfunction following chronic drug use is thought to play a major role in drug addiction. However, cortical pyramidal projection neurons can be subdivided into two major types (intratelencephalic (IT) and pyramidal tract (PT)), with distinct inputs and projection targets, molecular and receptor profiles, morphologies and electrophysiological properties. Yet, how each of these cell populations modulate behavior related to addiction is unknown. We demonstrate that PT neurons regulate the positive features of a drug experience whereas IT neurons regulate the negative features. These findings support a revised theory of cortical function in addiction, with distinct cells and circuits mediating reward and aversion.

Intermittent but not continuous access to cocaine produces individual variability in addiction susceptibility in rats.

Drug addiction is a chronic disease defined by a complex set of characteristics, including loss of control over drug intake and persistent drug craving, which primarily affects a small percentage of people who try drugs. Although many models have been developed to study individual aspects of drug use, there is great translational value in having an animal model that encompasses multiple aspects of the human disease, including the variation in severity observed in humans. Here, we describe an intermittent access model of cocaine self-administration that produces a subset of rats that display many of the core features of addiction, including escalation of drug intake, a binge-like pattern of drug use, robust locomotor sensitization, and high levels of drug-seeking during cue-induced reinstatement. This group is compared with rats that have the same drug history but do not develop this pattern of drug-taking and drug-seeking, as well as rats that undergo a traditional continuous access paradigm. Finally, we observe that high levels of cocaine consumption produce long-term changes in intracellular calcium signaling in the dorsomedial striatum.

Retrograde commercial colonic hydrotherapy.

OBJECTIVE: To ascertain the current practice of commercial colonic hydrotherapy in the UK and to collect data on the profiles of both the practitioners and their clients. In addition to understand how colonic hydrotherapy is perceived by those who use it and how much economic benefit it generates for the practitioners. Information as to training and complications was sought. PATIENTS AND METHODS: A questionnaire was sent to all 80 practitioners registered with the Association of Colonic Hydrotherapists (ACH) of the UK. The practitioners who responded were sent 10 questionnaires to be given to a group of consecutive clients. This client questionnaire included an SF-36 self-administered scoring system and a satisfaction survey. To understand the methodology and ritual of the hydrotherapy procedure a field trip was arranged and two of the authors (NJT and PJM) underwent one colonic hydrotherapy session with an experience practitioner. RESULTS: Thirty-eight (48%) of practitioners responded to our practitioner survey and 242 client questionnaires were returned. One third of practitioners reported a previous clinical background and 32 (83%) were single-handed practitioners. The average time in practice was six years and with an average age of the hydrotherapists being 50 years (22-78 years). Estimated number of sessions conducted were 3200 (range 140-10 000). Average annual income before expenses per practitioner was estimated at pound 45 675. The clients' ages ranged was 18 and 82 years of age (mean 44 years) and had undergone an average of 35 hydrotherapy treatments (range 1-2500). Clients had lower SF-36 scores than the UK norm. CONCLUSION: Colonic hydrotherapy is practised widely in the UK with an estimated 5600 procedures carried out by ACH practitioners monthly. It is not known how much activity is carried out by non-ACH members. ACH practitioners appear to be well trained and a proportion have medical backgrounds. Clients, who are often unhappy with orthodox medicine seem satisfied enough with the experience of colonic hydrotherapy to undergo regular purgings. No serious side-effects have been reported to us. Economic factors could be a driving force for the continuation of the practice as the monies earnt are not inconsiderable.