A pericellular basket is a presynaptic configuration of numerous axonal boutons outlining a target neuron soma and its proximal dendrites. Recent studies show neurochemical diversity of pericellular baskets and suggest that neurotransmitter usage together with the dense, soma-proximal boutons may permit strong input effects on different timescales. Here we review the development, distribution, neurochemical phenotypes, and possible functions of pericellular baskets. As an example, we highlight pericellular baskets formed by projections of certain Pet1/Fev neurons of the serotonergic raphe nuclei. We propose that pericellular baskets represent convergence sites of competition or facilitation between neurotransmitter systems on downstream circuitry, especially in limbic brain regions, where pericellular baskets are widespread. Study of these baskets may enhance our understanding of monoamine regulation of memory, social behavior, and brain oscillations. A pericellular basket is a presynaptic array of boutons from single or multiple axons that encase the target, postsynaptic cell body and proximal dendrites. Pericellular baskets ensheathing cerebellar and cortical neurons were described by Ramón y Cajal in the late 1800s and early 1900s. Pericellular baskets typically form postnatally after initial innervation of a brain region, suggesting possible induction by maturing target neurons. Pericellular baskets often deploy multiple neurotransmitters either coexpressed in individual axons or separately deployed by different axons, suggesting complex target cell regulation. The proximity to the postsynaptic soma of boutons configuring a basket suggests temporally precise inhibition or excitation of the encased cell. Pet1 neurons of the raphe nuclei offer an example of pericellular basket projections. Pet1 neuron pericellular baskets frequently target distant inhibitory GABAergic interneurons and thus may exert privileged influence on target region networks and their excitability. Cell types targeted by Pet1 neuronal pericellular baskets suggest possible roles in regulating memory durability. [ABSTRACT FROM AUTHOR]