Microtransplantation of cellular membranes from squid stellate ganglion reveals ionotropic GABA receptors

Luca Conti, Agenor Limon-Ruiz, Eleonora Palma, Ricardo Miledi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The squid has been the most studied cephalopod, and it has served as a very useful model for investigating the events associated with nerve impulse generation and synaptic transmission. While the physiology of squid giant axons has been extensively studied, very little is known about the distribution and function of the neurotransmitters and receptors that mediate inhibitory transmission at the synapses. In this study we investigated whether γ-aminobutyric acid (GABA) activates neurotransmitter receptors in stellate ganglia membranes. To overcome the low abundance of GABA-like mRNAs in invertebrates and the low expression of GABA in cephalopods, we used a two-electrode voltage clamp technique to determine if Xenopus laevis oocytes injected with cell membranes from squid stellate ganglia responded to GABA. Using this method, membrane patches containing proteins and ion channels from the squid's stellate ganglion were incorporated into the surface of oocytes. We demonstrated that GABA activates membrane receptors in cellular membranes isolated from squid stellate ganglia. Using the same approach, we were able to record native glutamate-evoked currents. The squid's GABA receptors showed an EC50 of 98 μmol l-1 to GABA and were inhibited by zinc (IC50 = 356 μmol l-1). Interestingly, GABA receptors from the squid were only partially blocked by bicuculline. These results indicate that the microtransplantation of native cell membranes is useful to identify and characterize scarce membrane proteins. Moreover, our data also support the role of GABA as an ionotropic neurotransmitter in cephalopods, acting through chloride-permeable membrane receptors.

Original languageEnglish (US)
Pages (from-to)47-52
Number of pages6
JournalBiological Bulletin
Volume224
Issue number1
DOIs
StatePublished - Feb 1 2013
Externally publishedYes

Fingerprint

Stellate Ganglion
Decapodiformes
GABA Receptors
squid
gamma-aminobutyric acid
gamma-Aminobutyric Acid
Cephalopoda
Membranes
Neurotransmitter Receptor
neurotransmitters
receptors
Oocytes
cell membranes
oocytes
Cell Membrane
Aminobutyrates
patch-clamp technique
synaptic transmission
Bicuculline
Xenopus laevis

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)

Cite this

Microtransplantation of cellular membranes from squid stellate ganglion reveals ionotropic GABA receptors. / Conti, Luca; Limon-Ruiz, Agenor; Palma, Eleonora; Miledi, Ricardo.

In: Biological Bulletin, Vol. 224, No. 1, 01.02.2013, p. 47-52.

Research output: Contribution to journalArticle

@article{b830c1fd7ae4428f9ba34b2f9036e0e8,
title = "Microtransplantation of cellular membranes from squid stellate ganglion reveals ionotropic GABA receptors",
abstract = "The squid has been the most studied cephalopod, and it has served as a very useful model for investigating the events associated with nerve impulse generation and synaptic transmission. While the physiology of squid giant axons has been extensively studied, very little is known about the distribution and function of the neurotransmitters and receptors that mediate inhibitory transmission at the synapses. In this study we investigated whether γ-aminobutyric acid (GABA) activates neurotransmitter receptors in stellate ganglia membranes. To overcome the low abundance of GABA-like mRNAs in invertebrates and the low expression of GABA in cephalopods, we used a two-electrode voltage clamp technique to determine if Xenopus laevis oocytes injected with cell membranes from squid stellate ganglia responded to GABA. Using this method, membrane patches containing proteins and ion channels from the squid's stellate ganglion were incorporated into the surface of oocytes. We demonstrated that GABA activates membrane receptors in cellular membranes isolated from squid stellate ganglia. Using the same approach, we were able to record native glutamate-evoked currents. The squid's GABA receptors showed an EC50 of 98 μmol l-1 to GABA and were inhibited by zinc (IC50 = 356 μmol l-1). Interestingly, GABA receptors from the squid were only partially blocked by bicuculline. These results indicate that the microtransplantation of native cell membranes is useful to identify and characterize scarce membrane proteins. Moreover, our data also support the role of GABA as an ionotropic neurotransmitter in cephalopods, acting through chloride-permeable membrane receptors.",
author = "Luca Conti and Agenor Limon-Ruiz and Eleonora Palma and Ricardo Miledi",
year = "2013",
month = "2",
day = "1",
doi = "10.1086/BBLv224n1p47",
language = "English (US)",
volume = "224",
pages = "47--52",
journal = "Biological Bulletin",
issn = "0006-3185",
publisher = "Marine Biological Laboratory",
number = "1",

}

TY - JOUR

T1 - Microtransplantation of cellular membranes from squid stellate ganglion reveals ionotropic GABA receptors

AU - Conti, Luca

AU - Limon-Ruiz, Agenor

AU - Palma, Eleonora

AU - Miledi, Ricardo

PY - 2013/2/1

Y1 - 2013/2/1

N2 - The squid has been the most studied cephalopod, and it has served as a very useful model for investigating the events associated with nerve impulse generation and synaptic transmission. While the physiology of squid giant axons has been extensively studied, very little is known about the distribution and function of the neurotransmitters and receptors that mediate inhibitory transmission at the synapses. In this study we investigated whether γ-aminobutyric acid (GABA) activates neurotransmitter receptors in stellate ganglia membranes. To overcome the low abundance of GABA-like mRNAs in invertebrates and the low expression of GABA in cephalopods, we used a two-electrode voltage clamp technique to determine if Xenopus laevis oocytes injected with cell membranes from squid stellate ganglia responded to GABA. Using this method, membrane patches containing proteins and ion channels from the squid's stellate ganglion were incorporated into the surface of oocytes. We demonstrated that GABA activates membrane receptors in cellular membranes isolated from squid stellate ganglia. Using the same approach, we were able to record native glutamate-evoked currents. The squid's GABA receptors showed an EC50 of 98 μmol l-1 to GABA and were inhibited by zinc (IC50 = 356 μmol l-1). Interestingly, GABA receptors from the squid were only partially blocked by bicuculline. These results indicate that the microtransplantation of native cell membranes is useful to identify and characterize scarce membrane proteins. Moreover, our data also support the role of GABA as an ionotropic neurotransmitter in cephalopods, acting through chloride-permeable membrane receptors.

AB - The squid has been the most studied cephalopod, and it has served as a very useful model for investigating the events associated with nerve impulse generation and synaptic transmission. While the physiology of squid giant axons has been extensively studied, very little is known about the distribution and function of the neurotransmitters and receptors that mediate inhibitory transmission at the synapses. In this study we investigated whether γ-aminobutyric acid (GABA) activates neurotransmitter receptors in stellate ganglia membranes. To overcome the low abundance of GABA-like mRNAs in invertebrates and the low expression of GABA in cephalopods, we used a two-electrode voltage clamp technique to determine if Xenopus laevis oocytes injected with cell membranes from squid stellate ganglia responded to GABA. Using this method, membrane patches containing proteins and ion channels from the squid's stellate ganglion were incorporated into the surface of oocytes. We demonstrated that GABA activates membrane receptors in cellular membranes isolated from squid stellate ganglia. Using the same approach, we were able to record native glutamate-evoked currents. The squid's GABA receptors showed an EC50 of 98 μmol l-1 to GABA and were inhibited by zinc (IC50 = 356 μmol l-1). Interestingly, GABA receptors from the squid were only partially blocked by bicuculline. These results indicate that the microtransplantation of native cell membranes is useful to identify and characterize scarce membrane proteins. Moreover, our data also support the role of GABA as an ionotropic neurotransmitter in cephalopods, acting through chloride-permeable membrane receptors.

UR - http://www.scopus.com/inward/record.url?scp=84875174269&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84875174269&partnerID=8YFLogxK

U2 - 10.1086/BBLv224n1p47

DO - 10.1086/BBLv224n1p47

M3 - Article

C2 - 23493508

AN - SCOPUS:84875174269

VL - 224

SP - 47

EP - 52

JO - Biological Bulletin

JF - Biological Bulletin

SN - 0006-3185

IS - 1

ER -