Uptake of the Neurotransmitter Histamine into the Eyes of Larvae of the Barnacle (Balanus amphitrite)

Abstract

The photoreceptors of adult barnacles use histamine as their neurotransmitter and take up (3)H-histamine selectively from the extracellular medium. We assayed for the uptake of (3)H-histamine into the eyes of the free-swimming (nauplius) and settling (cyprid) larval stages of Balanus amphitrite. The extracellular space of nauplii proved permeable to dyes below about 800 molecular weight (MW), indicating that (3)H-histamine (MW 111) introduced into seawater would have access to internal structures. (3)H-Histamine was taken up into nauplii by a process with a K(D) of 0.32 microM. Uptake was antagonized by chlorpromazine, which also blocks uptake of (3)H-histamine into adult photoreceptors. In autoradiographs of serial sections of nauplii and cyprids incubated in (3)H-histamine, the ocelli and compound eyes were labeled; other structures in the animal were not. No eyes or other structures were labeled with (3)H-serotonin, a related amine whose transporter commonly transports histamine as well. These experiments show that a histamine-specific transporter similar to that found in the adult is expressed in all of the eyes of barnacle larvae. In the ocelli, where photoreceptors and pigment cells may be distinguished in the light microscope, label was unexpectedly concentrated far more over the pigment cells than over the photoreceptors.

Evidence for the Presence of Histamine Uptake into the Synaptosomes of Rat Brain

“…Recently, selective Na + -dependent uptake of histamine into an arthropod photoreceptor was described in the literature [33][34][35] . [ 3 H]histamine uptake into photoreceptors decreases markedly by an excess of unlabeled histamine and by chlorpromazine and phenoxybenzamine.…”

The functional organisation of glia in the adult brain of Drosophila and other insects

“…While it is not yet known how this clearance occurs there are two possible routes: 1) direct reuptake into the photoreceptor terminal, or 2) uptake into the surrounding epithelial glia. The photoreceptors of barnacle nauplii Balanus amphitrite take up radioactively labelled histamine in a Na + dependent manner (Stuart et al , 1996; Stuart et al , 2002) but such studies do not clearly demonstrate that the uptake is direct, and not via an unidentified glial or pigment cell pathway. Corresponding evidence that Dipteran photoreceptors can take up histamine directly is lacking.…”

Presence and distribution of serotonin immunoreactivity in the cyprids of the barnacle Balanus amphitrite

“…The presence of a few signal molecules was suggested by experimental tests or immunohistochemical methods: histamine in B. amphitrite (Stuart et al, 2002) and acetylcholinesterase in B. amphitrite (Faimali et al, 2003). Furthermore, in the cyprid of B. amphitrite, serotonin and dopamine were detected by HPLC (Yamamoto et al, 1999), and an aromatic L-amino acid decarboxylase (AADC) gene, the product of which catalyzes, respectively, the synthesis of serotonin and dopamine from L-5-hydroxytryptophane and L-3,4-dihydroxyphenylalanine, was furthermore characterized (Okazaki and Shizuri, 2001).…”