Locally released small (non-protein) ninhydrin-reacting molecules underlie developmental differences of cultured medullary versus spinal dorsal horn neurons.

Neurons located in the trigeminal subnucleus caudalis (Vc) play crucial roles in pain and sensorimotor functions in the orofacial region. Because of many anatomical and functional similarities with the spinal dorsal horn (SDH), Vc has been termed the medullary dorsal horn--analogous to the SDH. Here, we report that when compared with embryonic SDH neurons in culture, neurons isolated from the Vc region showed significantly slower growth, lower glutamate receptor activity, and more cells undergoing cell death. SDH neuron development was inhibited in co-cultures of SDH and Vc tissues while Vc neuron development was promoted by co-culture with SDH tissues. Furthermore, we identified that small (non-protein) ninhydrin-reacting molecules purified from either embryonic or post-natal Vc-conditioned medium inhibited neuronal growth whereas ninhydrin-reacting molecules from SDH-conditioned medium promoted neuronal growth. These findings suggest the involvement of locally released factors in the region-specific regulation of neuronal development in Vc and SDH, central nervous system regions playing critical roles in pain, and point to novel avenues for investigating central nervous system regionalization and for designing therapeutic approaches to manage neurodegenerative diseases and pain.

Antidepressant use in psychiatry and medicine: importance for dental practice.

BACKGROUND: Many dental patients receive antidepressant therapy. However, antidepressants taken with other drugs may increase the risk of complications that require special dental precautions and care. METHODS: The authors conducted a retrospective study of 1,800 randomly selected patient records and evaluated the prevalence of using antidepressants and other medications concurrently. They analyzed antidepressant intake relative to drug classification and mechanism of action, age, sex and associated potential for clinical complications such as xerostomia, orthostatic hypotension and interaction with vasoconstrictors. The potential for additive adverse effects between antidepressants and other medications also was analyzed. RESULTS: Three hundred eighty-one (21 percent) of the 1,800 patient records indicated that patients were being treated with 412 antidepressants. Female subjects out-numbered male subjects by an approximate 2.3:1 ratio. Selective serotonin reuptake inhibitors were most commonly prescribed, followed by tricyclic antidepressants, atypical and third-generation antidepressants, and monoamine oxidase inhibitors. Based on reported medication intake, almost 58 percent of subjects in the antidepressant group were receiving treatment with two or more medications that had the potential for producing xerostomia. Two hundred fifty-seven (67 percent) of the 381 records documented intake of an antidepressant or other medication with orthostatic hypotension potential. CONCLUSIONS: Three hundred eighty-one patients reported that they were receiving antidepressant therapy for psychiatric and other medical reasons. Potential adverse effects and interactions with other medications have direct implications for dental treatment. CLINICAL IMPLICATIONS: Patients receiving antidepressant therapy are at risk of developing xerostomia and orthostatic hypotension, as well as experiencing the adverse effects of interaction with vasoconstrictors. Dentists must take appropriate precautions in treating these patients.