Revelations 22;
The Christian image of the tree of life is a tree that drinks from the water of life, and has twelve kinds of fruit.
Water symbolizes intellect and the clear water of life, is about intellectual clarity. The number twelve has many symbols such as the twelve tribes of Israel, the twelve apostles of Jesus, the twelve months of the year and twelve signs of the zodiac, to name a few. It symbolizes a form of natural order like the year that repeats while also evolving. The twelve tribes are a perpetual covenant handed down through generations, as civilization and times evolve.
Neurons are like little trees with neurons intertwined like the trees of a forest. The tree of life is on both sides of the river of life is an odd image, unless you see the tree of life as a forest of a type of type of tree; neurons, brain and human nature. Human nature is common to all human brain's.
The throne of god symbolizes the thalamus region of the brain which is the most wired part of the brain. This is the central switching station of the brain, accepting output from all areas of the brain and then integrates and distribute this data back to all area of the brain. The clear water of life is the flow back from the thalamus to the cerebral memory; triggers wisdom. The lamb is a gentle animal and reflects the calmness; neurotransmitters, needed to become conscious of this subtle output; see note below.
The number twelve types of fruit has to due with the firmware of the brain, or as Jung called them the archetypes of the collective unconscious. In terms of twelve we can get that number with 1 times 12, 2 times 6, 3 times 4. The first is the secular calendar, the second is the Old Testament;' two Star's of David (David and Jesus) and the last is the New Testament; trinity and cross.
The trees of life yields its fruit each month, which is sort of like a cyclic thalamus output that goes through the calendar with each month a new lesson; firmware fruit, over a different range of human thought. The leaves on any tree absorb light from the sun and undergo photosynthesis to create sugars for the plant's food. You can make a tea from the leaves of the tree of life, in sun warmed water of life, to heal all ills. This symbolism is about external reality helping to reinforce the internal changes that also occur.
Note: Neurotransmitters are used to alter the permeability of the neuron membrane, to either increase or decrease firing potential. Some neurotransmitters make the neurons leakier and will cause more firing, often over a wider scale. Other neurotransmitters do the opposite and will make it harder for neurons to fire, allowing the neurons and brain to increase the set point of the entropic potential. In the symbolism of the lamb, the latter is active. A higher entropic potential set point, with fewer pathways; less firing, creates thalamus to cerebral return clarity; water of life. Too much firing lowers the set point for less clarity and more noise.