In this issue of The Journal of General Physiology we begin a new initiative: Perspectives in General Physiology. The purpose of these Perspectives is to provide a forum where scientific uncertainties or controversies can be discussed in an authoritative yet open manner.

The Perspectives will be solicited by the editors—often based on recommendations by the advisory editors or members of the editorial board, who may be asked to coordinate the process. To frame the issue, two or more experts will be invited to present a brief point of view on the problem, which will be published back-to-back in The Journal. These Perspectives will be preceded by one or two editorial paragraphs that introduce the problem and invite the submission of comments in the form of letters to the editor, which will be published together in a single, predetermined issue (usually four months after publication of the Perspective). These letters may be no longer than two printed pages (approximately six double-spaced pages) and will be subject to editorial review. They may contain no more than one figure, and may not contain significant references to unpublished work. After the letters to the editor have been published, further responses will be limited to full manuscripts.

In the present issue of The Journal, we asked Kevin Strange and David E. Clapham to discuss the uncertainties surrounding the molecular identity of the outwardly rectifying, volume-sensitive chloride channel (or channels) that play a central role in the regulatory volume decrease that occurs in response to cell swelling induced by an osmotic perturbation. The functional characteristics of these channels have been studied extensively by many investigators, and a large number of possible candidate proteins have been proposed. As emphasized by Drs. Strange and Clapham, the list has undergone remarkable evolution: some early promising candidates should be stricken from the list, there is insufficient evidence about others, and there remains uncertainty about the current favorites, which are members of the CLC family of chloride channels. These questions are far from settled, but the present perspectives serve to narrow the scope of the problems that need to be resolved.

Letters to the editor related to this topic will be published in the September 1998 issue of The Journal of General Physiology. The letters should be received no later than June 15, 1998, to allow for editorial review. Letters can be submitted electronically, by sending a formatted text file as an attachment in an e-mail to the editorial office ( Figures must be submitted in hard copy (they can be faxed so that they are received in the editorial office by the June 15 deadline).