". . . learning, sex, and aerobic activity all increase neurogenesis."

First, let me say that educated folks who believe, think, or assume that people's brains do not regenerate are idiots.  Plain and simple.  And they're often times arrogant with their assumptions or stupid and uninformed and inexperienced views.  They believe that whatever abstract they read in a journal from JAMA or others is like word from Mt. Sinai. Which allows them to parrot what they read as truth.  And then be done with it and never have to think, review, or revise their ill-formed opinion. Everywhere that I've read about the adult brain has stated that people undergo neurogenesis their whole lives.  Period.  There are things that adults can do that will enhance this neurogenesis; those things are described below--exercise, eating fatty foods, and learning. A student asked me several years ago, "Sir, how can you grow more brain cells?"  I told her "Exercise."  Her 15-year-old reply was "Nah-ah."  Here is the article from Huffington Healthy Living:

Can adults grow new neurons? Until relatively recently, experts believed the answer was no.

But as neuroscientist Sandrine Thuret explains in a new TED Talk, humans can indeed generate new brain cells, a process called neurogenesis. More importantly, doing so has a range of important benefits, including improving mood, increasing memory formation and preventing the decline associated with aging.

Watch Thuret's talk for all of the details, but a few key takeaways are below.

Stress, lack of sleep, and aging all reduce the natural rate of neurogenesis. Certain medications also restrict new neuron growth. Thuret notes that some cancer patients unexpectedly develop symptoms of depression even after being told they are cured of their cancer. Unfortunately, the drugs they've received not only stop cancer cells from multiplying, but also stop "new neurons from being generated in their brain," she says, which has a negative impact on their mood.

Movement seems to be key to neurogenesis.

Conversely, learning, sex, and aerobic activity all increase neurogenesis.

In one of the first studies to highlight the links between aerobics and neurogenesis, Rusty Gage of the Salk Institute examined new brain cell growth in mice. The 'control' mice had no running wheel in their cages, while the 'runners' were able to run in their cages regularly. In the snapshots below, from Gage's experiment, the black dots are new neurons-to-be.

Thuret also explains how dietary habits are crucial to new neuron growth. 

Practices that increase neurogenesis include:

Calorie restriction of 20 to 30 percent.

Intermittent fasting (i.e., spacing the time between your meals)

Intake of flavonoids, which are contained in dark chocolate or blueberries.

Omega-3 fatty acids, present in fatty fish, like salmon.

Conversely, some dietary habits have a negative impact on neurogenesis, like diets rich in high saturated fat and alcohol consumption.

If you want to work on your brain, I would definitely heed that last caveat--avoid alcohol, including wine.  Wine growers around the world have done a superlative job at selling their products and marketing its health benefits.  Resveratol definitely helps your body, including your brain.  Just get it from a different source other than wine.  Don't get me wrong, sometimes wine just makes the company and the evening and the meal go better.  Sometimes you just want to give yourself over to mild decadence.  I say go for it.  But wine also dehydrates you.