Neuronal diversity of neuropeptide signaling, including galanin, in the mouse locus coeruleus.

The locus coeruleus (LC) is a small nucleus in the pons from which ascending and descending projections innervate major parts of the central nervous system. Its major transmitter is norepinephrine (NE). This system is evolutionarily conserved, including in humans, and its functions are associated with wakefulness and related to disorders, such as depression.

Neuropathic pain changes the output of rat lamina I spino-parabrachial neurons.

• Spared nerve injury (SNI) altered the action potential (AP) output of lamina I spino-parabrachial neurons (SPNs) without affecting their resting potential or membrane resistance. • In one-third of SPNs, high-threshold dorsal root stimulation elicited persistent AP firing which was never observed in cells from naïve animals. • 38% of SPNs from SNI rats showed spontaneous persistent AP firing.

Segmental and descending control of primary afferent input to the spinal lamina X.

Despite being involved in a number of functions, such as nociception and locomotion, spinal lamina X remains one of the least studied central nervous system regions. Here, we show that Aδ- and C-afferent inputs to lamina X neurons are presynaptically inhibited by homo- and heterosegmental afferents as well as by descending fibers from the corticospinal tract, dorsolateral funiculus, and anterior funiculus. Activation of descending tracts suppresses primary afferent-evoked action potentials and also elicits excitatory (mono- and polysynaptic) and inhibitory postsynaptic responses in lamina X neurons.

Distinct mechanisms of signal processing by lamina I spino-parabrachial neurons.

Lamina I spino-parabrachial neurons (SPNs) receive peripheral nociceptive input, process it and transmit to the supraspinal centres. Although responses of SPNs to cutaneous receptive field stimulations have been intensively studied, the mechanisms of signal processing in these neurons are poorly understood. Therefore, we used an ex-vivo spinal cord preparation to examine synaptic and cellular mechanisms determining specific input-output characteristics of the neurons.