Yes, when speaking of a chemical synapse; but no, not so much, when speaking of an electrotonic (gap junction) synapse.

There are two types of synapses in the nervous system: chemical synapses, and electrical synapses (also know as electrotonic synapses or gap junctions).

Chemical synapses have a small gap between two neurons, called the synaptic cleft, about 30nm across. At this gap, the two neurons do not touch (except for small molecules projecting from each and sticking to one another so as to keep the neurons in place to maintain the synapse; they are called synaptic adhesion molecules); the two neurons do not exchange their interior cellular fluid, the cytosol, nor any ions or other solutes. On receipt of a neural impulse, the pre-synaptic neuron releases Neurotransmitter chemicals into the synaptic cleft, which then diffuse across the synaptic cleft to the post-synaptic neuron, where they fit into receptors there and cause ligand-gated ion pores to open in the post-synaptic neuron, allowing sodium ions into it, which is the beginning of the neural signal in that neuron. The release of the neurotransmitter, its diffusion across the gap, the opening of the ligand-gated ion pores, and the entry of sodium ions takes a comparative long time, with the result that the synaptic delay for a chemical synapse is approximately 2 ms.

Electrical synapses have a much smaller gap between neurons, about 3.5nm, with pore structures spanning the gap, which allows ions in the pre-synaptic neuron to pass directly into the post-synaptic neuron. Since there is no need for the pre-synaptic neuron to release neurotransmitters, nor for them to diffuse across a comparatively large gap, nor to cause ligand-gated pores to open, the synaptic delay for an electrical synapse is shorter, approximately 0.2ms.

However, the difference in synaptic delay between chemical and electrical synapses may be less for mammals than for cold-blooded animals.