Taste papillae of the blowfly

✍ Scribed by Dethier, V. G. ;Hanson, F. E.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1965
• Tongue: English
• Weight: 630 KB
• Volume: 65
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030650112

✦ Synopsis

Each interpseudotracheal papilla on the oral surface of the labellum of the blowfly contains four bipolar neurons. An electrophysiological analysis has shown that one of these cells is a receptor which responds specifically to carbohydrates. The response consists of a rapid initial discharge which typically adapts to one-half maximum frequency in 300-400 msec. The response remains normal even i n the presence of choline chloride (1.5-2.0 M), NaCl (0.01-2.0 M ) , and CaClz (0.01-1.0 M). The various sugars tested shdwed the following order of increasing effectiveness:

Mannose, a nutritive sugar, is non-stimulating. D-arabinose, a n acceptable sugar, is more stimulating than L-arabinose, a n unacceptable sugar. L-arabinose, in contrast to D-, also stimulates other neurons i n the papilla.

Another cell responds when the electrode contains salt or certain carbohydrates such as L-arabinose. It is believed that its activity initiates behavioral rejection of compounds. It does not exhibit a high initial discharge or adaptation but waxes and wanes randomly. Its response to monovalent and divalent cations is similar although the latter produces volleys of high frequency.

Mechanical deformation causes a n increase i n frequency of a third spike. Mechanosensitive units may be classified by their responses into three classes: push, pull, or push-pull.

No evidence for a water receptor was found.