Table 2 Summary of induced effects on Tethya wilhelma Overview regarding induced contraction, endogenous contraction rhythm alteration and/or amplitude attenuation by substances used in the present and previous study, including effects on sponges, reported by other authors before.

Acetycholine

ionotrophic or metabotrophic acetylcholine receptor

Increased rhythm and intensity of contraction in Euspongia officinalis [22], no effect in Cliona celata [5]. Acetylcholine esterase activity in Sycon sp. 21, Hippospongia [35] and T. wilhelma [26]

Nicotine

agonist at ionotrophic acetylcholine receptor

Loss of current at high (cytotoxic) concentrations in Cliona celata [5]

Caffeine

antagonist at metabotrphic adenosine receptors

-

GABA^b

ionotrophic or metabotrophic GABA receptors

No effect in Cliona celata [5].

GABA/mgluR-like receptor gene in Geodia cydonium [19]. High specificity in inducing contractions in T. wilhelma (Ellwanger et al., submitted).

Glutamate^b

metabotrophic glutamate receptors

Induces intracellular Ca2+ increase. GABA/mGluR-like receptor gene in Geodia cydonium [19]. Lower specificity than GABA in inducing contractions in T. wilhelma [31]

Glycin

metabotrophic glycin receptors

-

Adrenaline

metabotrophic adrenergic receptor family

Slight current reduction in Cliona celata [5].

Histochemical detection in Sycon sp. [21]; increased rhythm and intensity of contraction in Euspongia officinalis [22]

Serotonine

ionotrophic or metabotrophic serotonine receptors

No effect in Cliona celata [5]. Histochemical detection in Sycon sp. [21], and Tedania ignis [42]

(by NOC-12)^c

intracellular soluble guanylate cyclase

NOS activity in heat stress response of Axinella polypoides and Petrosia ficiformis [48]

cAMP^d

metabotrophic cAMP receptor

Reduced locomotion an altered shape in dissociated Clathrina cerebrum cells [51];

Release of Spongilla lacustris gemmules from dormancy [50]