Nerve growth factor (NGF) induces sprouting of specific neurons of the snail, Lymnaea stagnalis

Abstract

Nerve growth factor (NGF) was examined for its ability to elicit sprouting by adult molluscan neurons. Motoneurons and interneurons (but not neurosecretory cells) from Lymnaea exhibited a sprouting response to murine 2.5S NGF in defined medium with a half-maximal response at about 150 ng/mL. Furthermore, an NGF antiserum blocked sprouting by all normally responsive neurons. We tested whether an NGF-like molecule is a component of conditioned medium (CM) by attempting to preabsorb its sprout-inducing activity with NGF antiserum. Treatment of CM with immune (but not nonimmune) serum largely blocked the response of motoneurons, but not that of neurosecretory cells, to CM. We conclude that NGF exerts neurotrophic activity on specific adult Lymnaea neurons, and suggest the possibility that an NGF-like molecule may exist in the molluscan nervous system.

Growth Factor Modulation of Substrate-Specific Morphological Patterns in Aplysia Bag Cell Neurons

“…In contrast to our findings, NGF as well as CNTF stimulate outgrowth from Lymnaea neurons in culture (plated on poly-L-lysine; Ridgway et al 1991;Syed et al 1996). However, in these studies only motor neurons and interneurons showed outgrowth in response to CNTF; neurosecretory cells were unresponsive.…”

Growth Factor Modulation of Substrate-Specific Morphological Patterns in Aplysia Bag Cell Neurons

“…In contrast to our findings, NGF as well as CNTF stimulate outgrowth from Lymnaea neurons in culture (plated on poly-L-lysine; Ridgway et al 1991;Syed et al 1996). However, in these studies only motor neurons and interneurons showed outgrowth in response to CNTF; neurosecretory cells were unresponsive.…”

Neurotrophic Actions of a Novel Molluscan Epidermal Growth Factor

“…The morphology of cells that responded to CM (Fig. 6 A) was similar to previous studies (Ridgway et al, 1991;Wildering et al, 1998). In contrast, L-EGF induced neurite outgrowth in only three of the six cell types tested, these being the RPA and PeA motoneurons and the visceral neurons VD2/3 (Fig.…”

“…The hypothesis that L-EGF is present in CM, whether in active or inactive form, corresponds more closely with the observation that L-EGF mRNA expression is upregulated in organ-cultured CNS, i.e., the source of CM-contained growth factors. Moreover, this idea is supported by our observation that L-EGF-induced neurite outgrowth is morphologically different from CM-induced outgrowth in the same types of cells, as well as by another study implicating other types of growth factors in the control of neurite outgrowth in Lymnaea (Ridgway et al, 1991).…”

Different extrinsic trophic factors regulate neurite outgrowth and synapse formation between identifiedLymnaea neurons

“…2), as it did in previous experiments (Ridgeway et al, 1991). The CM provided PeA neurons with sufficient trophic support to induce neurite outgrowth (92%, n ϭ 107; Fig.…”

Growth Factor Modulation of Substrate-Specific Morphological Patterns in Aplysia Bag Cell Neurons

“…In contrast to our findings, NGF as well as CNTF stimulate outgrowth from Lymnaea neurons in culture (plated on poly-L-lysine; Ridgway et al 1991;Syed et al 1996). However, in these studies only motor neurons and interneurons showed outgrowth in response to CNTF; neurosecretory cells were unresponsive.…”

Neurotrophic Actions of a Novel Molluscan Epidermal Growth Factor

“…The morphology of cells that responded to CM (Fig. 6 A) was similar to previous studies (Ridgway et al, 1991;Wildering et al, 1998). In contrast, L-EGF induced neurite outgrowth in only three of the six cell types tested, these being the RPA and PeA motoneurons and the visceral neurons VD2/3 (Fig.…”

“…The hypothesis that L-EGF is present in CM, whether in active or inactive form, corresponds more closely with the observation that L-EGF mRNA expression is upregulated in organ-cultured CNS, i.e., the source of CM-contained growth factors. Moreover, this idea is supported by our observation that L-EGF-induced neurite outgrowth is morphologically different from CM-induced outgrowth in the same types of cells, as well as by another study implicating other types of growth factors in the control of neurite outgrowth in Lymnaea (Ridgway et al, 1991).…”

Different extrinsic trophic factors regulate neurite outgrowth and synapse formation between identifiedLymnaea neurons

“…2), as it did in previous experiments (Ridgeway et al, 1991). The CM provided PeA neurons with sufficient trophic support to induce neurite outgrowth (92%, n ϭ 107; Fig.…”

Growth Factor Modulation of Substrate-Specific Morphological Patterns in Aplysia Bag Cell Neurons

“…In contrast to our findings, NGF as well as CNTF stimulate outgrowth from Lymnaea neurons in culture (plated on poly-L-lysine; Ridgway et al 1991;Syed et al 1996). However, in these studies only motor neurons and interneurons showed outgrowth in response to CNTF; neurosecretory cells were unresponsive.…”

Neurotrophic Actions of a Novel Molluscan Epidermal Growth Factor

“…The morphology of cells that responded to CM (Fig. 6 A) was similar to previous studies (Ridgway et al, 1991;Wildering et al, 1998). In contrast, L-EGF induced neurite outgrowth in only three of the six cell types tested, these being the RPA and PeA motoneurons and the visceral neurons VD2/3 (Fig.…”

“…The hypothesis that L-EGF is present in CM, whether in active or inactive form, corresponds more closely with the observation that L-EGF mRNA expression is upregulated in organ-cultured CNS, i.e., the source of CM-contained growth factors. Moreover, this idea is supported by our observation that L-EGF-induced neurite outgrowth is morphologically different from CM-induced outgrowth in the same types of cells, as well as by another study implicating other types of growth factors in the control of neurite outgrowth in Lymnaea (Ridgway et al, 1991).…”

Different extrinsic trophic factors regulate neurite outgrowth and synapse formation between identifiedLymnaea neurons

“…2), as it did in previous experiments (Ridgeway et al, 1991). The CM provided PeA neurons with sufficient trophic support to induce neurite outgrowth (92%, n ϭ 107; Fig.…”