TY - JOUR
T1 - Electrical coupling and excitatory synaptic transmission between rhythmogenic respiratory neurons in the prebötzinger complex
AU - Rekling, Jens C.
AU - Shao, Xuesi M.
AU - Feldman, Jack L.
PY - 2000/12/1
Y1 - 2000/12/1
N2 - Breathing pattern is postulated to be generated by brainstem neurons. However, determination of the underlying cellular mechanisms, and in particular the synaptic interactions between respiratory neurons, has been difficult. Here we used dual recordings from two distinct populations of brainstem respiratory neurons, hypoglossal (XII) motoneurons, and rhythmogenic (type-1) neurons in the preBötzinger complex (pre-BötC), the hypothesized site for respiratory rhythm generation, to determine whether electrical and chemical transmission is present. Using an in vitro brainstem slice preparation from newborn mice, we found that intracellularly recorded pairs of XII motoneurons and pairs of preBötC inspiratory type-1 neurons showed bidirectional electrical coupling. Coupling strength was low (<0.10), and the current that passed between two neurons was heavily filtered (corner frequency, <10 Hz). Dual recordings also demonstrated unidirectional excitatory chemical transmission (EPSPs of ~3 mV) between type-1 neurons. These data indicate that respiratory motor output from the brainstem involves gap junction-mediated current transfer between motoneurons. Furthermore, bidirectional electrical coupling and unidirectional excitatory chemical transmission are present between type-1 neurons in the preBötC and may be important for generation or modulation of breathing rhythm.
AB - Breathing pattern is postulated to be generated by brainstem neurons. However, determination of the underlying cellular mechanisms, and in particular the synaptic interactions between respiratory neurons, has been difficult. Here we used dual recordings from two distinct populations of brainstem respiratory neurons, hypoglossal (XII) motoneurons, and rhythmogenic (type-1) neurons in the preBötzinger complex (pre-BötC), the hypothesized site for respiratory rhythm generation, to determine whether electrical and chemical transmission is present. Using an in vitro brainstem slice preparation from newborn mice, we found that intracellularly recorded pairs of XII motoneurons and pairs of preBötC inspiratory type-1 neurons showed bidirectional electrical coupling. Coupling strength was low (<0.10), and the current that passed between two neurons was heavily filtered (corner frequency, <10 Hz). Dual recordings also demonstrated unidirectional excitatory chemical transmission (EPSPs of ~3 mV) between type-1 neurons. These data indicate that respiratory motor output from the brainstem involves gap junction-mediated current transfer between motoneurons. Furthermore, bidirectional electrical coupling and unidirectional excitatory chemical transmission are present between type-1 neurons in the preBötC and may be important for generation or modulation of breathing rhythm.
KW - Electrical coupling
KW - Excitatory transmission
KW - Newborn mice
KW - PreBötzinger complex
KW - Respiration
KW - Respiratory rhythmogenesis
KW - Type-1 neurons
UR - http://www.scopus.com/inward/record.url?scp=85051063727&partnerID=8YFLogxK
M3 - Journal article
AN - SCOPUS:85051063727
SN - 0270-6474
VL - 20
SP - 20
EP - 23
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 23
M1 - RC113
ER -